Not the best translation but interesting. Thanks to u/kokoniqq for the heads up!
1. Optical display scheme in AR glasses
Augmented reality technology, or AR technology, is to provide users with virtual information through images, videos, 3D models and other technologies while displaying real scenes, so as to achieve the ingenious integration of virtual information and the real world. It is the tipping point of the next information technology. According to authoritative predictions, augmented reality glasses will replace mobile phones as the next generation of collaborative computing platforms. Augmented reality technology represented by augmented reality glasses is currently emerging in various industries, especially in the security and industrial fields. Augmented reality technology embodies unparalleled advantages and greatly improves the way of information interaction. At present, the optical display solutions in the more mature augmented reality technology are mainly divided into prism solutions, birdbath solutions, free-form surface solutions, off-axis holographic lens solutions, and lightguide solutions.
1.1 Prism scheme
The prism scheme takes Google Glass as an example. As shown in Figure 1, the optical display system is mainly composed of a projector and a prism. The projector projects the image, and then the prism reflects the image directly into the human retina, superimposing it with the real image. Since the system is above the human eye, it is necessary to focus the eye to the upper right to see the image information, and this system has a natural contradiction between the field of view and the volume. The Google Glass system has a small field of view, with only a 15-degree field of view, but the optical lens has a thickness of 10mm, and the brightness is not enough, and the image has a large distortion, so the product was withdrawn by the company shortly after entering the market.
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Figure 1. Physical image of Google Glass glasses products
1.2 Birdbath solution
The optical design in the Birdbath solution is to project light from the display source onto a 45-degree beam splitter. The beam splitter has reflection and transmission values ​​(T), allowing the light to be partially reflected in the percentage of R, while the rest Transmitted in T value. At the same time, T allows users to see physical objects in the real world and digital images generated by the display at the same time. The light reflected from the beam splitter bounces onto the combiner. The synthesizer is generally a concave mirror that redirects light to the eyes. AR headsets using this optical display solution mainly include Lenovo Mirage AR headsets (Figure 2(a)) and ODG R8 and R9 (Figure 2(b)). Among them, ODG has a 50-degree field of view, and its thickness exceeds 20mm.
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Figure 2. (a) Mirage headset device; (b) ODG R9 headset device
1.3 Free-form surface scheme
The free-form surface scheme generally uses a free-form surface mirror with a certain reflection/transmission (T) value. The free-form surface is a complex and unconventional surface shape that is different from a spherical or aspherical surface, which is used to describe the surface shape of the lens. The mathematical expression of is relatively complicated and often does not have rotational symmetry. The light from the display directly hits the concave mirrocombiner and is reflected back into the eyes. The ideal position of the display source is centered and parallel to the mirror surface. Technically speaking, the ideal position is for the display source to cover the user's eyes, so most designs move the display "off-axis" and set it above the forehead. The off-axis display on the concave mirror has distortion, which needs to be corrected on the software/display side. Since free-form surfaces can not only provide more degrees of freedom for the design of optical systems, significantly improve the optical performance of the system, but also bring more flexible structural forms to system design, so it has become a research hotspot in the field of optical design in recent years. Among the most representative companies are Epson of Japan (shown in Figure 3) and the Meta series of Dream Vision Corporation of the United States (shown in Figure 4). Although the AR glasses of Epson of Japan are gambling in terms of color, saturation and image quality, they only have a field of view of 23 degrees and a thickness of 13mm. Although the Meta2 series of AR glasses from American Dreamland Vision has a 90-degree field of view, its thickness exceeds 50mm, and the weight of the optical and mechanical system alone is about 420 grams.
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Figure 3. AR glasses developed by Epson in Japan. (a) The actual product; (b) The imaging light path.
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Figure 4. AR helmet developed by American Dreamland Vision. (a) The actual product; (b) The imaging light path.
From the above, it can be seen that there is an unavoidable contradiction in the prism scheme, birdbath scheme, and free-form surface scheme, that is, the larger the field of view, the thicker the optical lens and the larger the volume. It is precisely because of this. The irreconcilable contradiction limits its application in smart wear, that is, augmented reality glasses.
1.4 Holographic lens solution
The holographic lens solution uses the unique optical characteristics of the holographic lens. The principle is to record a holographic collimating lens (Hd) and a simple linear grating (Hg) on ​​the same holographic dry plate, and the holographic collimating lens will emit the display source. The beam is collimated into a plane wave and diffracted into the substrate for total internal reflection transmission, while the line grating diffracts the beam into the human eye. This system uses holographic optical elements as coupling elements. It has a compact structure and reduces the difficulty of designing and processing holographic optical elements. At the same time, it reduces the dispersion of the holographic lens. It also has the advantages of large FOV and small size, so it is quickly adopted by people. accept. However, due to the relatively small eye movement range, and the holographic lens has complex aberrations and severe dispersion, the imaging effect of the holographic lens is not ideal. The representative manufacturer currently adopting the holographic lens solution is North. As shown in Figure 5, it is the physical map of North's AR glasses products based on the holographic lens solution and the schematic diagram of the imaging optical path.
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Figure 5. AR glasses based on holographic lens solution developed by North Company. (a) The actual product; (b) The imaging light path.
1.5 Optical waveguide solution
The optical waveguide solution has advantages in terms of clarity, viewing angle, volume, etc., so it has become the best optical display solution in augmented reality glasses, and is expected to become the mainstream optical display solution for AR glasses. AR glasses based on waveguide technology are generally composed of three parts: display module, waveguide and coupler. The light emitted by the display module is coupled into the optical waveguide by the in-coupling device, travels forward in the form of total reflection in the waveguide, and when it reaches the out-coupling device, it is coupled out of the optical waveguide and enters the human eye for imaging. Because the optical path is folded by the waveguide, the general system volume is relatively small. According to the principle of the coupler, the optical waveguide technology used in AR glasses based on waveguide technology can be divided into two types: geometric waveguide and diffractive optical waveguide.
The geometric waveguide solution generally includes a sawtooth structure waveguide and a polarized film array mirror waveguide (referred to as a polarized array waveguide). Among them, the mainstream polarized arrayed waveguide uses multiple semi-transparent and semi-reflective film layers that are placed in parallel and have a certain split ratio to achieve image output and exit pupil expansion, thereby having a thin, thin, large field of view and eye movement range. And the advantage of uniform color. The diffractive optical waveguide schemes mainly include surface relief grating waveguide scheme and volume holographic grating waveguide scheme. The embossed grating waveguide solution is manufactured using nano-imprint lithography technology. Although it has the advantages of large field of view and large eye movement range, it will also bring challenges to field of view and color uniformity, and related micro-nano processing technology. It is also a huge challenge, and the production cost is high. The volume holographic grating waveguide solution has advantages in color uniformity (no rainbow effect) and realization of a single-chip full-color waveguide, so it has attracted great interest from AR optical module manufacturers.
Figure 6 is the basic display principle of the waveguide solution. The coupling area is used to couple the light beam of the micro-projector into the waveguide sheet, so that the light beam satisfies the conditions of total reflection propagation in the waveguide sheet, and the coupling area is used for total reflection. The propagating light beam couples out of the waveguide and reaches the human eye. The coupling area can be mirrors, prisms, relief gratings and volume holographic gratings. The decoupling area can be half mirrors, relief gratings and volume holographic gratings arranged in an array. This article will explain in detail the polarization array waveguide scheme in geometric optical waveguide technology and the surface relief grating waveguide scheme and volume holographic grating waveguide scheme in diffractive optical waveguide technology, and the preparation and processing technology of surface relief grating and volume holographic grating At the same time, it further introduces the research and development situation of Goolton Technology in this field.
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Figure 6. Schematic diagram of the waveguide solution
2. Polarization array waveguide
2.1 Principle of Polarization Array Waveguide
The waveguide lens of the polarization array waveguide technology usually adopts a plurality of semi-transmissive and semi-reflective coatings placed in parallel and with a certain split ratio to achieve image output and exit pupil expansion. The semi-transparent and semi-reflective coating has angular selectivity. , And the array is arranged. The schematic diagram of its working principle is shown in Figure 7.After the light emitted by the image source is collimated by the eyepiece system, it is coupled into the waveguide by the reflective surface of the waveguide. The light in each field of view propagates in the waveguide according to the total reflection theorem, and the light enters the semi-transparent On the reverse side, part of it reflects out of the waveguide, and the other part of the transmission continues to propagate. Then this part of the advancing light meets another mirror, and the above-mentioned "reflection-transmission" process is repeated until the last mirror in the mirror array reflects all the remaining light out of the waveguide into the human eye. Since the waveguide can have multiple semi-transparent and semi-reverse surfaces, and each semi-transparent and semi-reverse surface forms an exit pupil, the exit pupil can be expanded when the substrate thickness is very thin to achieve a large field of view and large eye movement range. After multiple reflections, the emitted light can be "adjusted" to be more uniform.
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Figure 7. Schematic diagram of the working principle of the array optical waveguide
The pupil dilation technology of this technology is more complicated in design. Full consideration should be given to stray light, human eye compatibility, and various performance indicators when designing. In addition, uniformity is also an intuitive indicator of the end user experience. How to control the reflection and transmittance of multiple coatings, how to optimize the whole machine, and how to control the coating process can ensure the uniformity of the entire eye movement range. the focus of research. For this reason, Goolton Technology independently developed and designed optical modules based on polarization arrayed waveguide technology, and after repeated attempts to summarize, obtained epoch-making results.
2.2 Goolton Technology-"Seven-fold, dodecahedron" ultra-short-focus AR optical module M3010
Recently, Goolton Technology released a new "seven-fold, dodecahedron" ultra-short-focus AR optical module M3010 (Figure 8), which uses specially selected materials and process combinations to successfully eliminate the inherent noise and streaks of peer products Difficult problems such as perception, ghosting, distortion, dispersion, etc., have broken through the limits of AR display technology at this stage in terms of imaging clarity, maximum brightness, color uniformity, weight, volume, power consumption, light leakage, etc., and all indicators are in In the forefront of the world, it truly integrates all the advantages of optical waveguide modules such as extremely thin, extremely light and extremely high color reproduction, and exerts its performance to the extreme. Figure 9 shows the product specifications of the optical module M3010 based on polarization array waveguide technology recently launched by Goolton Technology.
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Figure 8. Goolton Technology-(a) Seven-fold optical path; (b) Product display diagram of optical module M3010 based on polarization arrayed waveguide technology
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Figure 9. Goolton Technology-Product Specifications of Optical Module M3010 Based on Polarization Arrayed Waveguide Technology
Goolton Technology’s "seven-fold, dodecahedron" ultra-short-focus optical module M3010 has the following super performance. 1. Small: Based on the anisotropic characteristics of the crystal material, the multiplexing of optical devices is realized, and the light that originally propagated in one direction in the optical waveguide is folded into 7 segments, which reduces the volume of the projector unit by 85%; 2. : Weight is about 33 grams; 3. Transparency: The light transmittance of the waveguide lens exceeds that of ordinary architectural glass windows, which can reach more than 85%; 4. Thin: Refraction distortion is less than 2mm; 5. Color: ultra-high contrast, resolution, color reproduction The M3010 comes standard with LCOS as the image source, and the resolution can reach 1920*1080. It provides optical resolution close to the limit resolution of the human eye, completely eliminates the sense of screen boundary, and the image quality is clear and delicate, and the image contrast Sharp, no graininess. The maximum brightness can reach 5000nit, and the color gamut coverage is more than 100% RGB, reaching the level of professional monitors. 6. Zero light leakage: Thanks to the light splitting film array waveguide sheet and optical structure exclusively developed by Goolton Technology, the M3010 module will not leak light when working, and will not expose the content displayed on the screen to the outside world, regardless of the concealment requirements The extremely high military helmet is also the AR glasses for consumer entertainment, this feature is very important; 7.Super vision: M3010 adopts top-down structure, the horizontal field of view is completely unobstructed, and the entire field of view is fully visible. While improving the user experience, it also solves the problem of security risks caused by users wearing glasses to block the line of sight; 8. Low power consumption: battery life can reach about 10 hours; 9. Mass production reaches 10K pieces per year, and the mass production yield is stable. The cost has reached the world-class level; 10. Ultra-strict environmental testing standards: In the face of extreme high and low temperature environments, as well as high humidity and continuous salt spray, Goolton Technology’s "seven-fold, dodecahedron" ultra-short-focus AR optics The module M3010 can work stably with reliability far exceeding the industry average; 11. Fully accept customization: AR glasses have rich landing scenes, based on the powerful functions of M3010, technology companies from all walks of life can work in their familiar Customize a wide range of intelligent AR products in the field. We firmly believe that Goolton Technology’s "seven-fold, dodecahedron" ultra-short-throw optical module M3010 will definitely be able to kick off the next generation of display technology revolution, and provide better and more advanced technology for companies that also hold the spirit of craftsmanship. Powerful AR products and high-quality services.
3. Diffractive optical waveguide
3.1 Surface relief grating waveguide
The relief grating waveguide solution is to use relief grating (SRG) instead of traditional catadioptric optical device (ROE) as the coupling in, coupling out and exit pupil expansion device in the waveguide solution. The schematic diagram of its working principle is shown in Figure 10.
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Figure 10. Schematic diagram of the principle of diffractive optical waveguide and surface relief grating
Commonly used relief gratings are mainly one-dimensional gratings, including tilted gratings, trapezoidal gratings, blazed gratings and rectangular grating structures. Figure 11(a) shows the scanning electron microscope (SEM) image of the tilted grating. The two-dimensional grating is mainly a hexagonal cylindrical grating structure commonly used in waveguides. Figure 11(b) shows the SEM image of the two-dimensional cylindrical grating structure. The feature sizes of the above grating structures are all nanometers. Currently, the most representative products of the embossed grating waveguide solution are Microsoft's HoloLens series 12(a) and WaveOptics' embossed grating waveguide series 12(b).
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Figure 11. (a) Tilted grating structure diagram; (b) Two-dimensional cylindrical grating structure diagram
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Figure 12. (a) HoloLens2 from Microsoft; (b) Embossed grating waveguide from WaveOptics
3.2 Volume holographic grating waveguide
The volume holographic grating waveguide solution uses a volume holographic grating as the coupling in and out of the waveguide. A volume holographic grating is an optical element with a periodic structure. It is generally exposed through a double-beam holographic exposure, directly on the micron-level thickness of the photopolymer The internal interference of the film forms interference fringes with light and dark distribution, which causes the periodic change of the refractive index inside the material. This period is generally a nano-scale grating structure, which is an order of magnitude with the wavelength of visible light, so the light can be effectively modulated, and the incident light can be diffracted to change the direction of light transmission. Combining the volume holographic grating and the waveguide film, the diffraction efficiency of the volume holographic grating can be adjusted by designing the relevant parameters of the volume holographic grating (such as material refractive index n, refractive index modulation factor and thickness, etc.).
The schematic diagram of the working principle of the volume holographic grating waveguide technology is shown in Figure 13.The image generated by the microdisplay becomes parallel light after passing through the collimating system. The diffraction effect changes the propagation direction of parallel light. When the light in the waveguide meets the condition of total reflection, it is confined to travel in the waveguide direction without loss. When the parallel light propagates to the holographic grating at the out-coupling end, the condition of total reflection is destroyed, and the light is diffracted again and becomes parallel light that exits the waveguide and enters the human eye for imaging. When the coupled holographic grating and the modulated out holographic grating have the same periodic structure and mirror symmetry, the dispersion can be effectively eliminated.
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Figure 13. Schematic diagram of the working principle of volume holographic grating waveguide technology
The representative manufacturers that adopted volume holographic grating waveguide solutions in the early days were Sony and Digilens. With the maturity of this technology, the number of companies participating in the optical research of holographic grating diffraction waveguides is increasing, mainly including TruLife and WaveOptics in the United Kingdom, and Akonia in the United States. Wait. Sony has produced a high-brightness single-green volume holographic grating waveguide. As shown in Figure 14, the structure uses a double-sided volume holographic grating as the coupling end, achieving a transmittance of 85% and a display brightness of 1000cd/m2. However, due to the small thickness of the volume holographic grating, the efficiency of the system is low. In addition, it can only be used for monochromatic display and has been discontinued. Digilens launched a double-layer full-color volume holographic grating waveguide, as shown in Figure 15. This structure realizes color by using multiple monochromatic gratings, which can effectively reduce the crosstalk of system colors, but the efficiency of the system is not high, and because of its The double-layer waveguide structure makes the system more difficult to manufacture.
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Figure 14. Sony's double-sided volume grating structure holographic waveguide. (a) The actual product; (b) The imaging light path.
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Figure 15. Digilens full-color volume holographic grating waveguide. (a) The actual product; (b) The imaging light path.
Goolton Technology uses the holographic material exposure method to combine the RGB three colors into a diffractive waveguide, and uses the principle of coherent recording and diffraction to transmit the image to the human eye for display. There are three aspects: simulation design, materials, and process preparation. Simulation design requires self-written complex calculation models; materials mainly refer to the photosensitive materials in HOE. For holographic optical waveguides, low shrinkage ratio, high efficiency and high uniformity before and after manufacturing are required; in terms of process, more holographic technology is required Manufacturing light path and exposure experience, it is very related to the materials used. Figure 16 shows the corresponding display effect of the single-layer full-color volume holographic grating waveguide developed by Goolton Technology, with a field of view of 30°.
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Figure 16. The display effect of the single-layer full-color volume holographic grating waveguide developed by Goolton Technology
4. Micro-nano manufacturing of diffractive optical waveguides
4.1 Micro-nano fabrication of surface relief grating waveguide
Surface relief gratings can be divided into one-dimensional and two-dimensional gratings from the dimension, and can be divided into straight gratings, blazed gratings and inclined gratings in structure. Since the augmented reality optical waveguide is used in the visible light band, in order to achieve greater diffraction efficiency and field of view, its characteristic size is generally hundreds of nanometers or even tens of nanometers, and its performance has a small tolerance for errors. Processing and preparation posed great challenges. The current preparation of diffractive optical waveguides is basically based on semiconductor preparation processes (such as photolithography and etching processes). However, because these methods are limited by their complicated and expensive equipment, the production cost is very high, and they are not suitable for mass production of optical modules.
Shown in Figure 17 is the process flow chart of surface relief grating template preparation or small batch preparation, including its scanning electron micrograph. For straight gratings, the process is relatively mature. First, a resist layer is spin-coated on the substrate, and the grating is patterned by interference exposure or electron beam exposure, and then reactive ion etching (RIE) or inductively coupled plasma etching is used ( ICP) transfer the pattern to the substrate and remove the resist layer to complete the preparation of the straight grating. Due to the uniformity problem, the oblique grating optical waveguide represented by HoloLens cannot be directly prepared by the reactive etching scheme, so the preparation process is more complicated, and focused ion beam etching (FIBE) and ion beam etching are required. Beam etching, IBE), reactive ion beam etching (reactive ion beam etching, RIBE) technology. Considering efficiency and uniformity comprehensively, RIBE is a more suitable solution. First, a hard mask (such as Cr) layer is plated on the substrate by physical or chemical methods, and then a resist layer is spin-coated. Also use interference exposure or electron beam exposure for patterning, and then transfer the resist pattern to the Cr layer through a chlorine dry etching process. After the etching process, the remaining resist layer is stripped by oxygen plasma method. Next, the fluorine-based RIBE process is used to incident the substrate with an ionized argon ion beam at an oblique angle. After the reactive ion beam etching, the Cr mask is removed by a standard wet etching process to obtain an oblique grating with excellent uniformity.
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Figure 17. Surface relief grating template or small batch preparation process
The above-mentioned semiconductor-based manufacturing process is expensive and not suitable for mass production and processing of grating waveguides. Therefore, the replication process of diffractive optical waveguides was developed to achieve mass production, and this large-scale manufacturing process relies on optical resins with high refractive index. At present, Magic Leap and WaveOptics have carried out verification of related processes. The replication process includes hot embossing, UV-nano imprint lithography and micro contact printing (also known as soft lithography). Among them, ultraviolet nanoimprint lithography is a common method in mass production of surface relief grating waveguides.
The specific process flow is shown in Figure 18. The process can be divided into two stages: nanoimprint work mold preparation stage and mass production stage. First, the pattern is processed on the silicon wafer to be used as a template through the above-mentioned template preparation process, and UV resin is spin-coated on a larger silicon wafer through nanoimprint technology and more templates are printed on it. The printed structure is then exposed to ultraviolet light to fix the resin. Finally, the multi-pattern imprinting mold is mass-produced by repeating the above process. In the mass production process, multi-pattern molds are used to produce surface-relief grating waveguides, then functional coatings are used to cover the waveguides, and laser cutting technology is used to separate them, and finally the waveguides of different structures are stacked to realize the preparation of optical modules.
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Figure 18. Mass production process flow of surface relief grating replication
4.2 Micro-nano manufacturing of volume holographic grating waveguide
The key element of the volume holographic waveguide is the volume holographic grating. The preparation of the volume holographic grating makes use of the characteristics of holographic technology. Two plane light waves with a certain angle excited by laser interfere with each other, and the interference pattern is exposed and attached to the substrate. It is obtained by forming interference fringes on the photosensitive material, and the material properties change according to the intensity distribution of light. Finally, a material with periodic changes in refractive index is obtained. The materials for preparing volume holographic waveguides include silver halide, dichromate gelatin, photosensitive polymers, holographic polymer dispersed liquid crystals, and other more exotic materials.
Holographic technology is a method that uses the principle of optical coherence to record and obtain the amplitude and phase information of an object light wave. It uses the principle of interference recording and diffraction reproduction to record the interference fringes generated by the interference of the object light wave with amplitude and phase information and the reference light wave into a hologram in the form of intensity distribution, thereby recording all the amplitude and phase information of the object light wave in On photosensitive materials. Holography is an active coherent imaging technology. The holographic recording optical path (as shown in Figure 19(a)) mainly completes two functions. One is to complete the coherent illumination of the measured object, which is formed by the transmission or reflection of the object. The object light wave; the second is to use the reference light wave to interfere with the object light wave to form a hologram.
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Among them, T0 represents the zero-order diffracted light, which corresponds to the transmitted light wave of the reference light wave; T+1 represents the +1-order diffracted light, which carries the information of the original object light wave; T-1 is the -1 order diffracted light, which carries the object light wave Conjugation information. In optical holography, the +1-order diffracted light can form a virtual image of the object, which can be directly observed with eyes, while the -1st-order diffracted light can form a real image of the object, which can be received by the screen.
Figure 19. Schematic diagram of the recording and reproduction process of optical holography
The diffraction order of the ideal holographic grating is only 0 and ±1 orders. The holographic optical waveguide display uses the 0th order light to be continuously totally reflected in the optical waveguide, while the -1 order light continuously emits from the waveguide surface. The geometrical schematic diagram of grating diffraction is shown in Figure 20.
Figure 20. Schematic diagram of holographic grating diffraction geometry
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From the above three equations, it can be concluded that for a specific wavelength, waveguide medium and light incident angle, the grating period that meets the total reflection condition should meet certain conditions.
According to its structure, holographic gratings can be divided into transmission type and reflection type holographic gratings. The fundamental difference between the two is that the recording method is different, that is, the propagation direction of the two recording lights is different, which causes the different orientation of the interference fringe surface in the recording material. When the transmission type holographic grating records, the object light and the reference light are incident from the same side of the recording medium, while when the reflection type holographic grating records, the object light and the reference light are incident from both sides of the recording medium.
Holographic gratings can be divided into surface holographic gratings and volume holographic gratings according to the relative thickness relationship between the thickness of the recording medium and the interference fringe spacing. The evaluation criteria of surface holographic grating and volume holographic grating are characterized by Q value. When Q≥10, it is volume holographic grating, otherwise it is surface holographic grating.
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The microstructure of volume holographic grating is inside the volume grating, so its diffraction is mainly the volume effect of the material. When the incident light satisfies the Bragg condition, the volume holographic grating will have extremely high diffraction efficiency, and if it deviates from the Bragg condition, the diffraction efficiency will drop rapidly. This characteristic makes the volume holographic grating have obvious angle and wavelength selectivity. When used as a coupling device, a volume holographic grating can couple light with a specific wavelength and angle in the waveguide out of the waveguide without blocking the view of the real scene from the outside, so it is an ideal coupling device.
The above-mentioned preparation process of volume holographic grating is only suitable for small batch verification, and for mass production, it is necessary to develop a more economical solution. Companies represented by Sony and DigiLens have developed the processing process of volume holographic waveguide. The roll-to-roll process for preparing volume holographic waveguides is shown in Figure 21. First, the double-beam interference exposure method is used to form volume holographic waveguides in the photosensitive polymer film attached to the roll; the second step is to form high-quality cycloolefin polymer plastic waveguides by injection molding. In order to obtain a qualified image, the warpage of the waveguide must be less than 5um, and the thickness change of the effective area should be less than 1um. Then the transfer process of the holographic optical element is carried out to accurately align and paste the holographic waveguide film with the plastic waveguide; then the plastic holographic waveguide is cut; finally in the color matching process, the red and blue plastic waveguides and the green plastic waveguide are aligned and used with UV The resin encapsulates and fixes it. The plastic substrate should remain flat before and after each processing is a challenge faced by both the stamping and color matching processes.
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Figure 21. Preparation process of roll-to-roll holographic waveguide

FOREX Strategies

What are FOREX Strategies?
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You may have noticed that most of people confuse the terminology and refer to FOREX Strategies in the wrong way. There are methodologies, systems, strategies, and techniques. The most effective methodology is Price Language (Trend Tracking). Combined with a correct reading of mass psychology presented by the charts.
We know that in the Stock Markets there are thousands of strategies. FOREX, like the rest of the markets, presents you with the opportunity to apply similar strategies to win consistently. Taking advantage of repetitive psychological patterns.
First, the Price Language methodology has created great fortunes in FOREX, and the next fortune may be yours. But this methodology must be implemented within a framework of advanced concepts of Markets. Without forgetting the basics. And working hard day by day.
Second, a strategy is a set of parameters and techniques that together give you the advantage to act in any situation. Thus for example in war, generals have attack strategies and counterattack strategies.
FOREX strategies alike are entry strategies and exit strategies. All beginners should know these FOREX strategies for beginners. That way you will get a general idea of ​​the game and understand that trading is a war against the Market and its Specialists. Only applying FOREX strategies revealed by the same Specialists and using their own techniques,
... you can survive in this war.
Do not fall into the trap of the many "systems" and "methods" that are offered on the internet about operating in the FOREX Market. They just don't work in the long run. They are strategies based on indicators for the most part. Using rigid parameters. That if they can work and give profitability during a certain period of time, they will always reach a breaking point when the market changes its dynamics.
Instead, take advantage of your precious time and learn the Language of Price or Price Action.
The Language methodology will allow you to adapt to each new phase of the Market. If you combine this knowledge with the appropriate psychological concepts, you can live comfortably from speculation in FOREX.

Forex Trading Strategies Reddit - Basic FOREX Strategies

You have two basic FOREX strategies, one entry, and one exit. Both follow a general strategy that helps you capitalize on the collective behaviors of the Market. That is, of the total of participating speculators.
This behavior causes the formation of cycles that repeat over and over again. Driven by the basic emotions (uncertainty, greed, and panic) of the speculators involved that can be taken advantage of with the aforementioned FOREX strategies. Specialists identify these emotions in the order flow and capitalize on these events every hour, every day, and every month.
Basic FOREX Strategies - The Price Cycle
These repetitive cycles consist of 4 phases:

1. Accumulation
2. Upward trend
3. Distribution
4. Downward trend

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The two trends can be easily identified by their notorious breakdown. And the two areas of uncertainty (accumulation and distribution), due to their notorious range trajectories.
This general behavior determines the core of our FOREX strategies.
You buy when the price of a pair has broken and has come out of one of its congestion formations (accumulation or distribution). You implement one of the Forex strategies, in this case, the entry one.
The multi-time technique will help you find the point of least risk when entering your initial buy or sell order. In the same way and using the same strategy but this time to close your position, the multiple timing technique will also show you how to close your operation obtaining the highest possible profit.
The most consistent way to extract profits in the market is by trading the start of trends within a cycle . Once confirmed by their respective breaks from the areas of uncertainty. This is the mother of all FOREX strategies . And in a market that operates 24 hours, we have more frequent cycles and therefore more opportunities.

Forex Trading Strategies Reddit - Advanced Forex Strategies

There are many advanced FOREX strategies that are generally used by professional speculators working for large financial firms.
Among these firms are banks, Investment Fund managers and Hedge Fund managers. The latter is an investment modality similar to Investment Funds, with the difference that Hedge Funds use more complex investment strategies. Its operations are more oriented to aggressive speculations in the short and medium-term.
Among the most common strategies is hedging (hedging), carry trade, automated systems based on quantum mathematics. And a large number of combinations between the different option strategies.

The Carry Trade

The central idea of ​​Carry Trade is to buy a pair in which the base currency has a considerably higher interest rate than the quoted currency. To earn the difference in rates regardless of whether the price of the pair rises or falls.
Suppose we buy a $ 100,000 lot of AUDJPY, which according to the rates on the chart would turn out to be the ideal instrument in this example to use the Forex carry trade strategy.
As our capital is in US dollars we have to assume for our example, the following quotes necessary to perform the place calculations:
AUD / JPY = 80.00 USD / JPY = 85.00
What happens internally in your broker is this.

1. By placing as collateral $ 1,000 of your $ 50,000 of capital (assumed for this example), deposited in your account, you have access to $ 100,000 virtual (this is what is known as leverage); that is, you put in $ 1,000 and your broker lends you 99,000.
2. With those $ 100,000 virtual dollars, your broker borrows on your behalf ¥ 8,500,000 Japanese yen (85 × 100,000) at 0.1% annual interest from a Japanese bank.
   
3. With those ¥ 8,500,000 Japanese yen, your broker buys A $ 106,250 Australian dollars (8,500,000 / 80) and deposits it in an Australian bank where it receives 4.5% annual interest on your behalf.
   
4. One year later (and regardless of the profit or loss generated by the pair's movement), your profit will be the difference between the AUD rate and the JPY rate, that is:
   

Profit = (AUD rate) - (JPY rate) - (costs of the 2 currency exchanges) Profit = (4.5%) - (0.1%) - (0.1% to 1%)
The great advantage of carry trade FOREX strategies is that this percentage profit is applied to the $ 100,000 of the standard lot; the broker transfers all of the profit to you, even if you only contributed $ 1,000. On the other hand, if you carry out the inverse of this operation, this benefit of the Forex carry trade becomes a cost (swap), and you assume it completely.
Remember that FOREX carry trade strategies are recommended for pairs with considerable interest rate differences, such as the one we have just seen in our example.
These FOREX strategies should also not be used in isolation. The idea is that through technical analysis you identify when would be the ideal time to enter the market using your carry trade Forex strategy and multiply your profits considerably.

What FOREX Strategies Do Hedge Funds Use?

The FOREX strategies used by large fund managers do not constitute an advantage in terms of percentage results for them, nor do they constitute a competitive disadvantage for you.
The vast majority of them fail because of their big egos. In fact, there was a firm made up of great financial geniuses, including 2 winners of the Nobel Prize in Economics, who developed a strategy based on quantum mathematical calculations.
With an initial base capital of about 3 billion dollars, and after 3 successful years obtaining annual returns of over 40%, the firm Long-Term Capital Management, begins its fourth year with losses. To counteract these losses the geniuses decide to multiply the initial capital several times, while the losses continued.
The year closed with the bankruptcy of the fund, and with a total accumulated loss of 1 trillion dollars, due to the great leverage used. And all for not admitting that the FOREX Strategies of Long Term Capital Management were not in line with the dynamics of the Market.
There are an overwhelming number of opportunities in the stock markets to make money interpreting the Language of Price.
You don't need to use complex "advanced" strategies that have been created to handle hundreds or billions of dollars.
The reasons for using these FOREX strategies are very different from what a "retail trader" pursues with his small speculation business.
As you can see, you should not worry about wanting to integrate any of these advanced strategies into your arsenal. They are only beneficial for managing hundreds or billions of dollars, where the return parameters are very different when you handle small amounts of capital.
Do not worry about collecting hundreds of free FOREX strategies that circulate on the internet, that great accumulation of mediocre information will only serve to confuse you and waste your valuable time.
Spend that time learning Price Action,
… And you will always be one step behind the Specialists, identifying each new Market condition, and anticipating the vast majority of reversals of all prices.
Ironically, the most successful fund managers indicate that their most profitable trades are those based on the basic trend-following strategies of the Price Language. The same ones that you will learn in this Free Course.
Dedicate yourself to perfecting them and believe me you won't need anything else. As long as you have good risk management, taking into consideration the following points ...

Styles of Investments in FOREX

The Investment FOREX long term is not recommended for small investors like you and me. If we take into account the term investing literally as large investors do who buy a financial product today to sell it years later.
We both have a better niche in the short and medium-term.
You may have noticed that the big multi-year trends in the Forex Market do exist. But minor swings within a big trend are usually very wide.
These minor movements allow us to easily double and triple the annual return of the big general trend, motivating most traders to speculate in the short and medium-term.
These minor oscillations or trends that occur within the large multi-year trends owe their occurrence mainly to two reasons.
First, the FOREX Market presents 3 sessions a day each in different cities of the world with different time zones (Asia, Europe, and America). This causes more frequent trend changes than in the rest of the stock markets.
Second, the purpose for which it was created also plays a role. The modern Foreign Exchange Market, since its inception in 1972, was conceived by the global financial system as a tool for speculation. To obtain benefits in the short and medium-term (from several days to 1 year).
These two points are basically the reasons why we observe the immense speed with which the FOREX market changes trends.
For example, for those who live in America, in the early morning (Europe) the EURUSD pair may be on the rise, in the morning or afternoon (America) it may be down, and then finally at night (Asia) it may return to the rise.

Define your Own Style for your FOREX Investments

One of the first decisions you will have to make is to choose your style as a trader or investor.
There are 4 types of well-defined styles.
Most professional traders tend to have multiple styles, although they always identify with one primary style for their FOREX investments. Study the characteristics of the 4 main styles to make your investments in FOREX :
1. Long Term: recommended for anyone who is going to enter the market for the first time and who can dedicate a minimum of one hour per month to their investments in Forex. The period of an open position ranges from 1 year to 5 years.
2. Medium Term: recommended for anyone who is going to enter the market for the first time and who can dedicate a minimum of one hour per week to their investments in Forex. The period of an open position ranges from 1 month to 1 year.
3. Short Term: recommended for anyone who is going to enter the market for the first time, or who already has a certain time operating in the long and medium-term, showing constant profits, and who can dedicate a minimum of one hour per day to your investments in FOREX. The period of an open position ranges from 1 day to 1 month.
4. Intraday : recommended only for people with a fairly solid earnings record in the short term, and with a capital greater than $ 50,000. As we have noted, this option constitutes a full-time job.
People who start investing in FOREX , should start executing short-term (weeks) and medium-term (months) transactions only, and not pay attention to intraday oscillations (day trading).
If you are interested in being an intraday speculator, I recommend that you first exhaust at least a year doing operations in the short and medium-term to assimilate the correct strategies and to develop the necessary mentality to carry out this work.
The second option would be to participate in some kind of intensive training.
I remind you that self-educating is almost impossible in speculation. You are likely to accumulate a lot of knowledge by reading books and attending courses. But you will probably never learn to make money with all the incomplete "systems" circulating on the internet.

Mistakes to Avoid When Looking for Your Style

Many people who are new to FOREX investments make the mistake of combining these styles, which is a key to failure.
I recommend that if you are not getting the results you expected by adopting one of these styles, do not try to change it. The problem sure is not in the style, but in your strategies or in your psychology.
A successful investor is able to make a profit in any longer trading time than he is used to. I explain. If you are already a profitable operator in the short term, it is very likely that you will also be profitable in the medium and long term,
… As long as you can interpret the Language of Price or Price Action.
In the opposite case, the same would not happen. If you were a medium-term trader, you would need time to adjust to the intraday. The reality is that long, medium and short term traders have very similar personalities. The intraday trader is completely different.

The Myth of the Intraday in Investments in FOREX

If you are already successful in the short, medium and long term, you will notice that the sacrifice and the hours necessary in front of the computer to operate intraday is much greater. The intraday style will be useful to increase your account if it is less than USD $ 100,000 in a very short time in exchange for 8 to 12 hours a day of hard work but ...
You must first develop the necessary skills to operate the intraday.
The ideal is to combine all the styles to get more out of the Market and carry out more effective transactions and have a diversification in your investments in FOREX.
There are intraday traders that are very successful, but the reality is that there are very few in the world that make a profit year after year. If you want to become an intraday, you just have to prepare yourself properly through intensive training.
Otherwise, I recommend that you don't even think about educating yourself to adopt the intraday style. It is not necessary to go against a probability of failure greater than 99%. Unless
... your ego is greater than your common sense.
The main reason why this style of investments in FOREX is not recommended for the vast majority of us "retail investors" (the official term "retail traders"), is the high operational cost.
The real commissions in this market range between $ 2.0 and $ 2.50 for each lot of 100,000 virtual units. This means that a complete operation (opening and closing) is approximately $ 5.00, for each standard lot traded ($ 100,000 virtual).
Another fundamental reason is the advent of robotic traders (HFT = High-Frequency Trading), which tend to manipulate the market in the shorter intraday swings. Please do not confuse HFTs with automated systems that we find daily on the internet, and that can be purchased for a few hundred dollars and often for free on FOREX forums / groups.
These HFTs to which I refer, they are effective. They cost millions of dollars and have been developed by the large Wall Street financial firms to manage their investments in FOREX.
The reality of the intraday trader is that you execute orders for large lots at the same time, to profit from the smallest movements in the market. It is an activity based on reflexes. The slightest oversight or distraction can turn into a catastrophe for your FOREX investments.
I recommend that you start investing in FOREX using slow time periods such as H4 or Daily. For some reason, all Goldman Sachs intraday FOREX investments are made with algorithms.

Finally…

To choose your style as a trader and manage your investments in FOREX, first determine what your degree of experience is, analyze the points mentioned below and the rest you will discover when you execute your first operations.
The points that will affect your decision are:

• Capital
• Time available each day
• Level of Experience
• Personality

Discovering your style is a search process. For some it will be a long way to find the right time frame that matches their personality. Don't be put off by the falls. After all, those who continue the path despite the falls are the ones who reach the destination.
And I hope you are one of those who get up over and over again. The next lesson will boost your confidence when you discover the main reason that moves currencies ...

Fundamental Analysis in Forex Trading Reddit

The fundamental analysis in Forex is used mostly by long-term investors. Players as we saw in the styles of operators, start a negotiation today, to close it years later.
I always emphasize the importance that the mass media give to this type of analysis to distract the great mass of participants.
It is all part of a great mass psychological manipulation. For centuries the ignorance of the masses has been organized before the great movements begin.
The important news are the macroeconomic reports published by the Central Banks and other government agencies destined for this work. All reports are made up. 99% of them are corrected months later.
These events are tools to justify fundamental analysis and price cleaning movements. Any silly headline does the job. With this, it is possible to absorb most of the existing liquidity, before the new trend phase is projected.

Reaction!

Except in rare situations, the result of an economic report of the fundamental analysis is generally already assimilated in the graph. In most cases, there are financial institutions that already have access to this information and are organizing and carrying out their operations in advance.
The phrase buy the rumor and sell the news is a very old adage on Wall Street. And its meaning contains what we have just explained. For the investor who can interpret the Language of Price, fundamental analysis is of little importance. Well, in general, their disclosure does not indicate that you have to take any action in your open trades , as long as your entry strategy provides you with a good support cushion.
This reality of fundamental analysis causes a lot of confusion for investors who lack in-depth knowledge of the forex market.

Macroeconomic Data

The data published in these events is irrelevant. Both for speculators and for the people in general. They are false. They lack reliability.
The price can go up or down with the same result of the data. The main ones are:
- Interest Rates - GDP (gross domestic product) - CPI (inflation) - ISM (manufacturing index) - NFP (payroll) - Double Deficits (deficit = fiscal + balance of payments)
If you are initiated, I recommend you avoid operating near these events. It is only a matter of having the time pending. Use the economic calendar for Fundamental Analysis of Forex Factory.
There is a probabilistic advantage in operating these fundamental analysis events. But it takes preparation, experience, and practice. They represent a way of diversifying in the general operation of a speculator.

The Uncertainty of Fundamental Analysis

On many occasions after the disclosure of an economic report, the price movement of the currency pair that is going to be affected tends to move in the opposite direction to the logic of the report.
I show you an example of a fundamental analysis report. Imagine that the EUR / USD pair is trading at 1.2500, and the FED (US Federal Reserve) issues a statement announcing that it has just raised inter-bank interest rates from 0.25 points to 0.75 points. Very positive news for the US dollar that logically implies an appreciation of the currency and consequently an instantaneous collapse of the EUR / USD pair (up the dollar and down the euro)
However, minutes after the release of said fundamental analysis report, the pair after effectively collapsing to 1.2400, returns and returns to its levels prior to the report (1.2500). This situation is very common , but it is not so easy to identify it when it is occurring, but after the damage is done.
Traps like these devour the accounts of beginners who approach the market with little experience, with weak strategies, and especially with very little experience.
That is why I reiterate that you forget the fundamental analysis for now. Just keep in mind when operating, that there is no publication scheduled nearby. Just check the economic calendar for the day and forget about the numbers. Let the economists mess around with the data.

FOREX Market Correlation

The Forex market correlation exists between pairs with similar "base" currencies and not always under the same circumstances. The correlation in the Forex market that is most followed and that has the greatest impact on fundamental analysis is that of the US dollar (USD).
The USD is the most traded monetary unit with a volume greater than 80% with respect to the rest of the currencies. This fact determines why their correlation is the most important, the most followed, and perhaps the only one worth following in the fundamental macro analysis.
The 7 major pairs are usually in sync . These 7 pairs all include the USD and present a fundamental analysis correlation almost 75% of the time. Influencing the rest of the currency pairs.

Advantages of the FOREX Market Correlation

In the fundamental analysis the most basic FOREX correlation is the following. When the USD appreciates, the USD / CAD, USD / CHF, and USD / JPY pairs tend to go up in price. This indicates that the Canadian dollar (CAD), the Swiss franc (CHF), and the Japanese yen (JPY) are losing value against the USD.
We must bear in mind that this correlation does not occur 100% of the time. In fact, the JPY generally tends to move in the opposite direction , since in recent decades this currency has been used as a source of financing to invest in other financial instruments.
On the other side is the FOREX market correlation that generates a movement almost in unison in the other 4 major pairs EUR / USD, GBP / USD, AUD / USD, and NZD / USD. These tend to fall in price, homologous the appreciation of the USD. But not always.
In this case the fundamental analysis correlation works most of the time, between 65 and 85% of the time. Small differences are noted in the extent that each of these pairs experiences.
There is also a correlation in the secondary FOREX market, where the pairs of all currencies that do not include the USD participate, but I recommend you not to waste time on them for now. There are more important things about the Language of Price to know first.

FOREX Commodity Correlation

In this part I will explain to you in a basic way the Correlation Commodities - FOREX of the fundamental analysis.
There are three currencies that have a direct correlation with commodities. They are usually called: "COMDOLLS" which is short for "Commodities Dollars" (Commodities Dollars), since all three obey the dollar denomination. These are:
- The New Zealand Dollar (NZD) - The Australian Dollar (AUD) - The Canadian Dollar (CAD)
These three currencies make up the group of the 8 largest together with the euro, the pound, the yen, the franc and the US dollar. Together, they merge to produce the major pairs traded in the FOREX Foreign Exchange Market.
The FOREX Commodity Correlation has an affinity in most cases greater than 75%. And each of them has its different raw material of correlation. You will notice that the NZD and the AUD are two currencies that act practically in unison. Both present minimal discrepancies in their fluctuations in the short, medium and long term.
This is mainly because their economies are very similar and their economic and fiscal policies are too. Their main production items also show great similarities, despite the fact that the Australian economy is much larger than the New Zealand economy.
The raw materials that follow the movement of the AUD are mainly gold and copper. If you put the history of these three quotes during the last decade of the year 2,000 together on the same chart, you will notice a very similar upward movement between the three quotes. Pure correlation of fundamental analysis.
This strong correlation with commodities in the metals area for the AUD has provided Australia with an economic advantage enviable over the other major powers that have seen their currencies devalue sharply against the AUD. At the same time, they experience a constant decrease in the purchasing power of their citizens.
The NZD maintains a correlation with raw materials related to agriculture and livestock, mainly including milk and its derivatives. It is one of the countries that dominates the world export of these economic items, and also has important exports of metals , although in smaller quantities than Australia.
Finally, you have a correlation with raw materials in the energy area. For historical reasons the CAD, which is not the largest oil producer in the world, but an important supplier to the largest consumer that is the US, has seen its currency oscillate in line with oil prices.
To make long-term investments in the Foreign Exchange Market, it is necessary to take into consideration at least one Commodity Correlation - FOREX in your fundamental analysis.

Forex Technical Analysis Reddit

The technical analysis is the methodology that interprets the movements of the price. Specialists look for liquidity to fund their business. The repetition of the strategies used by the specialists in their work generate repetitive patterns.
If you were an analyst, you would develop the visual ability to identify such patterns on a graph. If you were a programmer you would quantify them mathematically using complex formulas.
And if you could learn to interpret the Language of Price, you would have the ability to anticipate 90% of all movements that occur on a chart. And in this business, anticipating is what will make you money.
Market prices are reflected and framed on a horizontal time axis and a vertical price axis. Prices go up or down according to the aggressiveness of the participating operators. In an efficient or balanced market these oscillations should be imperceptible.
But in reality this is not the case, since the Market works thanks to the digital printing of hundreds of billions of units of paper money systematically distributed by the Central Banks through the banking system. These resources serve as a tool to manipulate 100% of the movements that occur in the FOREX Market.
Are you looking for Technical Indicators? All technical indicators were created from the 70's. How do you think that for more than 200 years the speculators of the past accumulated great wealth?
With the Language of Price. The best timing is given by the price itself. Indicator-generated entry signals usually occur at the wrong time.
The basis of technical analysis is human psychology. Unfortunately, human beings are not perfect and are loaded with emotions that dominate their behavior in similar situations, creating repetitive and highly predictable behavior when it occurs in masses.
The study of technical analysis through indicators and subjective training, originates and shapes the collective thinking on which all the traps that specialists execute every day to maintain their business are designed. If the majority won, the Market would cease to exist.
Although you already know that the patterns are not generated by the masses , but the repetitive behavior of the Specialists in the face of the action response of the masses. It is very easy for speculaists, because they can see everyone's orders in their books.
And they also exert a great influence on the decisions of the masses through the mass media. It is what I call the war between the Egg and the Stone , if you hit me you win and if I hit you also you win.

The Deception of Modern Technical Analysis

Through the centuries thousands of people have been able to extract great benefits from the financial markets by applying the basic strategies of technical analysis and the psychology of the Price Language.
More than 200 years ago when the markets began to operate officially, fundamental analysis predominated, which was only used by large financial institutions. As this analysis tool began to become popular, these institutions began to apply the strategies of technical analysis.
In recent decades and with the massification of internet technology, technical analysis has begun to be handled by anyone who has a computer with internet access. The same financial institutions, which have been present for more than a century and as a result of this overcrowding , establish a strategy to confuse and misinform about the true strategies of technical analysis.
This has been accomplished in the following manner. Currently there are hundreds, if not thousands of technical indicators that have been developed by so-called "gurus" of technical analysis and that sell their magic indicators packed in a "system" or "method" that usually cost thousands of dollars, or simply with the publication of a book with which they generate large profits. Double benefit.
The aim is to confuse the initiates in speculation and create the collective mentality that will originate the same behaviors over and over again. About 95% of these new entrants completely lose all the capital they invest in their early stages as investors.
Leaving them with a negative experience and creating the idea and the image that financial markets are an exclusive area for geniuses with high academic levels and that only they can produce returns in the markets year after year.
The initiate, having lost all his original capital, turns to these “gurus” for help and teachings. You spend more capital on the products they offer you and the cycle repeats itself . Obviously, the vast majority do not relapse and completely forget to re-engage in the stock markets.
I hope you have not been a victim of this drama.
Now I will show you the simplicity of a FOREX technical analysis , without the need to resort to any indicator as a tool to determine an effective entry or exit strategy when planning your operations.

The Price Cycle

Previously you studied in the FOREX strategies lesson, that the typical price cycle when it is reflected in a graph, presents four very specific phases and very easy to identify if you perform a technical analysis with common sense . These are:

• Accumulation
• Bullish trend
• Distribution
• Bearish trend

Remember also that the most effective way to constantly extract profits in the markets is by taking advantage of phases 2 and 4 (the trends). Combined with a correct reading of the collective behavior of the masses of speculators interpreting the Language of Price.
You will be surprised by the simplicity with which thousands of people around the world and over the centuries have accumulated large sums of money by drawing a few simple lines and applying responsible risk management with their capital.

How to Identify Trends?

Being able to determine the trend phases within the price cycle is the essence of technical analysis since it is these two phases that provide you with the probabilistic advantage you need to operate in the markets and obtain constant returns.
In the most plain and simple language, in the world of technical analysis, there are only two types of formations: trends and ranges.
The trends, in turn, can be bullish if they go up, or bearish if they go down. The ranges, on the other hand, can be accumulation if they are at the beginning of the cycle, or distribution if they are in the high part of the cycle. As I had indicated in the topic of FOREX strategies when describing the price cycle.
This sounds more like a play on words, but I will show you the practical definition to simplify your life and then you will apply these definitions on the graph so that everything makes more sense to you.

• Bullish trend: a succession of major highs and major lows
• Bearish trend: a succession of minor highs and minor lows
• Floor Range: equal highs and varied lows
• Ceiling Range: equal minimums and varied maximums

https://preview.redd.it/vvmsshf0guv51.png?width=600&format=png&auto=webp&s=c321679a7dcc03f7184778be86379ef442fddf91
Some key points from the graph:

• The start of this big uptrend was detected when the last high (thick green line) of the previous downtrend was broken to the upside, ending the succession of lower highs, while exiting the lateral floor formation.
• The succession of major lows in the uptrend (thin blue lines)
• The succession of major highs in the uptrend (thin green lines)
• The end of the uptrend was detected when the last low (thick blue line) of the uptrend was broken to the downside, ending the succession of higher lows, while exiting the lateral ceiling formation.

A tool that will help you sharpen your technical eye and identify trends on the chart is the Currency Scanner. This application is very effective and will provide you with a much-needed boost in your operations to identify reliable trends. At first, we are not sure how reliable a trend is. You will receive great help to find opportunities with the Currency Scanner .

The Common Sense, The Less Common of Senses

The central idea of ​​technical analysis consists in determining the price situation of a market, that is, in which phase of the pattern of its cycle it is currently conjugated with the collective thinking of the masses and the possible traps that the market would have prepared to remove. the capital at stake by the public.
To carry out a precise technical analysis, you will use the support and resistance lines, which can be static (horizontal) or dynamic (projecting an angle with respect to the horizontal axis).
Your common sense prevails here.
If you show a 10-year-old a chart, they will be able to tell you if the price is going up or down. You will most likely have no idea how to draw the lines, but you will be able to establish the general trend. Simply using your common sense.
By introducing indicators and other gadgets , the simplicity and effectiveness of the technical analysis created by your common sense evaporates.
The following graph conceptually shows you all the possible situations in which you could draw these lines to carry out your technical analysis of the place. You can clearly observe a downtrend delimited by its dynamic trend line and an uptrend on the right side with its respective dynamic delimitation.
https://preview.redd.it/5iehg0r6guv51.png?width=500&format=png&auto=webp&s=84c265a5d35da7ea970792c4bf40fe20b33bd8bd

Forex Charts Analysis

I want to remind you that the formations or patterns that develop on the charts (triangles, wedges, pennants, boxes, etc.) only work to execute trades that have initially been confirmed by the static support and resistance lines and to read the collective thinking of the masses.
Chart formations work, but you must know the Language of Price to determine when the Specialists will exploit a chartist figure, or when they will allow it to run. In fact, you will learn with the Language that you can operate a chart figure in any direction.
Much of the "mentalization" that the masses receive is to believe that the figures are made to be respected. Which is an inefficient way of working. Simply because you could wait days or months for a perfect chart figure to occur in order to perform a reliable trade. When in fact there are dozens every day.

Japanese Candles

Of all the tools you have to carry out technical analysis, perhaps the best known and most popular is the Japanese technique of candles (candlesticks).
Candles are mainly used to identify reversal points on the chart without resorting to confirmation of horizontal trend lines and only using a previous bar or candle breaks.
Its correct use is subject to a multi-time analysis (multiple temporalities) and a general evaluation of the context proposed by the market in general at the time of each scenario.
Later I will show you all the important details to take into account so that you use Japanese candles in a simple and very effective way.
Do not forget ... Trading in your beginnings based on formations (chartism) and candlestick patterns conjugated with hundreds of tools and technical indicators, constitutes the perfect path to your failure. Before using any strategy or technique I recommend you focus on learning the Price Language, which includes 3 basic things:

• The Price: structure and dynamics
• Market sentiment: relative strength, external shocks, etc.
• Psychology: flexible mindset and risk acceptance

After you acquire this solid foundation, I guarantee that you will be able to trade any trading system that exists, any strategy, technique or chart figure in a profitable and consistent manner.
Specialists make money every day at the expense of the collective behavior caused by the use of these strategies and techniques. With which you will only manage to lose your capital and your time by putting the cart in front of the horse.
People who do the opposite, at best become,
... Philosophers of Speculation, or indocile Robot Assistants or Expert Advisors.
To make money in any market condition, range or trend, you must use the technical analysis based on the Price Language and combine it with a correct psychological reading of the price. This knowledge can only be acquired through proper education and lots of supervised practice. Like any other career in life.
I hope you've found this guide helpful!

Hello all,
I've never learned about quaternions before, and it finally came up that I need to understand them to implement rotations in my game (being made in Unity). I decided to take the time to learn and understand them well, and one thing that helps me retain what I learned is to share/explain it to others in a way that is simple to understand.
So that is why I'm making these posts. This first part will be explaining what quaternions are - i.e. their mathematical definition. The next part will be a simple tutorial on how to use quaternions to rotate game objects in Unity.
DISCLAIMER: I myself have not gone in that much depth on the subject, I learned just enough to understand the basics, and this post will be a summary of that. Also, it's best to have a basic understanding of Linear Algebra and complex numbers to fully understand everything this post covers.
While I will be linking the sources that I used to learn from, I want to give a special shout out to this site right here: https://eater.net/quaternions/. They explain quaternions beautifully and simply using interactive videos that greatly visualize the concepts. I highly recommend checking that out.
That said, I hope you will find this and benefit from it. Please let me know in the comments if I have made any mistakes in my explanations or if I could improve on them in some way.

Basic terms

When discussing the rotation of an object, there are two types of coordinate frames that are important to know: the inertial frame, and the body frame.
The inertial frame can be thought of as the fixed frame of reference of an object - the rotation will always be applied from the inertial frame.
The body frame is the frame that shows the object's position and rotation relative to the inertial frame.
So when applying a rotation, what it essentially means is to perform the mathematical transformation of a vector from the inertial frame to the body frame.
See Figure 1 below for a simple visualization:
Fig. 1: The inertial frame (blue) transformation to the body frame (yellow) [1]

The need for quaternions

3D rotation is much easier to understand when using Euler angles: you have the three separate axes that you can rotate on in 3D space: x, y, and z. For each axis, you would pretty much handle the rotation on the plane perpendicular to that axis - which essentially is like performing 2D rotation for each dimension.
To rotate all 3 axes at once, you would basically put the formulas for rotating each individual axis in a matrix and multiply that matrix with the vector (from the right) to end up with the resulting rotated vector. See the figures below for a better understanding:
Fig. 2: The inertial frame - the frame of reference of an object [2]
Fig. 3: Rotation matrix from the inertial frame to body frame [2]
However, Euler angles cannot solve every case of 3D rotation, as it can suffer from the "Gimbal Lock." This occurs when the angle on one axis approaches 90 degrees, which results in the object only being rotatable in 2 dimensions on the other axes, as they are positioned in a way such that rotating on one of the two remaining axes has the same range of angular motion as the other.
To eliminate this problem and have the ability to rotate in all 3 dimensions at all times, we turn to black magic quaternions.

What are quaternions?

Mathematically speaking, a quaternion is a 4-element vector that can be used to encode any rotation in a 3D coordinate system. Generally speaking, it is actually a special kind of complex number, where the imaginary part is a 3-dimensional vector.
Example: q = a + v => a is the real part, which is a scalar, and v is the imaginary vector defined as: v = (xi, yj, zk), where i, j, and k can be thought of as unit complex vectors in the x, y, and z axes, respectively.
As a 4D vector, it can be represented like this: q = [a x y z]
When used in the context of 3D rotations, you can think of the imaginary/vector part as being the axis that the body will rotate on, and the real/scalar part as being the angle of rotation. More specifically, if theta is the angle of rotation, and v is the axis vector, then the rotation quaternion q = [a b c d] - called the attitude quaternion - is defined as follows:
Fig. 4: attitude quaternion [3]
Before discussing the formula for quaternion rotation, we must discuss quaternion multiplication. Quaternion multiplication, although long and tedious to do by hand, is not very different from the multiplication of two complex numbers in rectangular form. NOTE: the following is only one way to define quaternion multiplication, but it is by far the simplest to understand.
The Hamilton Product of two quaternions is essentially done by expanding each quaternion and multiplying them using the distribution law, similar to multiplying polynomials in algebra:
Let q1 = a1 + b1i + c1j + d1k and q2 = a2 + b2i + c2j + d2k be two quaternions. Their resulting product is:
q1q2 = (a1 + b1i + c1j + d1k)(a2 + b2i + c2j + d2k) = ... = (see result below)
Fig. 5: resulting product of two quaternions [3]
NOTE: order matters! Like matrix multiplication, quaternion multiplication is not commutative, meaning q1q2 != q2q1.
All that said, the formula for rotating a vector from the inertial frame to the body frame is:
Fig. 6: formula for quaternion rotation [3]
Where q^bi is the attitude quaternion as defined earlier, (0 vI) is the inertial frame vector to rotate, represented as a quaternion with a 0 real part, and (q^bi)^-1 is the inverse of the attitude quaternion.
The inverse of a quaternion is similar to the conjugate of a complex number, where you simply invert the sign of the imaginary part. For a quaternion, you invert the sign of all the components of the vector part.
Example: q = a + v => q^-1 = a - v

This all seems counter-intuitive

...is what you might be thinking - because that's what I thought as well when I first read all this.
My main questions were:

• Why does the attitude quaternion multiply the input angle by 0.5?
• Why do you bother multiplying the input vector by the attitude quaternion if you're going to immediately multiply that result by the inverse of the attitude quaternion? Wouldn't that negate the initial multiplication?

To answer the first question: the attitude quaternion halves the input angle because of the nature of the rotation formula, in which you sandwich the input vector between the attitude quaternion and its inverse. If you don't halve the angle, you essentially end up rotating the vector by double the input angle.
The second question is much more difficult to explain simply, so I will do my best to put it in my own words according to what I've learned:
Before the actual explanation, I have to define what a stereographic projection is. In simple terms, a stereographic projection is a mapping of an entity of a higher dimension onto an entity of a lower dimension. A simple, practical example of stereographic projection is mapping the Earth's globe onto a 2D map of the world.
When you perform a quaternion multiplication, geometrically speaking you're performing a stereographic projection of a 4-dimensional hypersphere (which is beyond our perception) onto 3-dimensional space.
So when you perform the first multiplication from the right - i.e. the attitude quaternion by the input vector (0, v) - the resulting projection causes vector v is rotated by the angle of the attitude quaternion, which is 0.5 * theta, on the attitude quaternion's rotation axis - i.e. its "vector" part. However, the object represented by the input vector would be distorted due to that projection, if you were to apply that transformation on all the points that make up that object.
Therefore, to undo the distortion effects of the hypersphere projection, we need to multiply the result mentioned above by the inverse of the attitude quaternion. This will rotate the object by the theta * 0.5 again while applying the "reverse" projection, undoing the distortions caused by the previous transformation.
This results in the complete rotation of the object by angle theta. The overall multiplication first rotates it halfway while distorting it, and then it rotates it the rest of the way undoing the "damage" done by the first multiplication.
You can get a better explanation and visualization of the above section at https://eater.net/quaternions/.
Thank you for reading this whole thing if you got to this point, and I hope you benefit from this as much as I have benefitted from writing it!

Sources

I will be splitting the sources in two sections: one for all the sources that I got information from to write this, and the other one for the figures that I directly took screenshots from. The one I can't stress enough to check out if you want to understand quaternions is: https://eater.net/quaternions/.
Sources of Info

• Euler Angles (Wikipedia): https://en.wikipedia.org/wiki/Euler_angles
• Euler Angles (chrobotics): http://www.chrobotics.com/library/understanding-euler-angles
• Gimbal Lock visualization #1: https://youtu.be/zc8b2Jo7mno?t=67
• Gimbal Lock visualization #2: https://youtu.be/Mm8tzzfy1Uw?t=285
• Quaternions (chrobotics): http://www.chrobotics.com/library/understanding-quaternions
• Quaternions (Wikipedia): https://en.wikipedia.org/wiki/Quaternions_and_spatial_rotation
• Quaternions explanation with interactive video: https://eater.net/quaternions/

Figures
[1]: https://en.wikipedia.org/wiki/Inertial_frame_of_reference#Newton's_inertial_frame_of_reference
[2]: http://www.chrobotics.com/library/understanding-euler-angles
[3]: http://www.chrobotics.com/library/understanding-quaternions