Optical system

Abstract

The present application provides an optical system, which includes a projector, a deflector, a polarizer, a first grating coupler structure and a second grating coupler structure. The projector emits three light beams with different wavelengths. The deflector is disposed below the projector and is configured to change the incident angles of the three light beams and focus the three light beams on a same area of the first grating coupler structure. The first grating coupler structure is disposed below the deflector and is configured to couple the three light beams into a light guide lens such that the three light beams travel a same optical path in the light guide lens. The light guide lens is connected to the first grating coupler structure and is configured to transmit the three light beams. The polarizer is disposed between the projector and the deflector and is configured to filter out transverse electric or transverse magnetic modes of the three light beams. The optical system of the present application can reduce the thickness of optical elements and provide high efficiency RGB light (image).

Description

Technical Field

[0001] This invention relates to an optical system, and more particularly to an optical system comprising a variable structure of a deflector. Background Technology

[0002] Grating couplers are used to transmit images by guiding external light through a light guide lens on an optical device. However, for color images, the external light includes several wavelengths with different colors, such as RGB light. When color images of different wavelengths are coupled into the same light guide lens, the optical paths of the RGB light will be different due to their different first diffraction angles, resulting in imaging problems in the output area of ​​the grating coupler. Therefore, it is necessary to solve the above problem. Summary of the Invention

[0003] One aspect of this invention is to provide an optical system. The optical system includes a projector, a deflector, a polarizer, a first grating coupler structure, and a second grating coupler structure. The projector emits three beams with different wavelengths. The deflector is disposed below the projector and configured to change the incident angle of the three beams and focus them into the same region of the first grating coupler structure. The first grating coupler structure is located below the deflector and configured to couple the three beams to a light guide mirror, such that the three beams travel the same optical path within the light guide mirror. The light guide mirror is connected to the first grating coupler structure and configured to transmit the three beams. The polarizer is disposed between the projector and the deflector and configured to filter out the transverse electric (TE) mode or transverse magnetic (TM) mode of the three beams. The second grating coupler structure is disposed on the light guide mirror and configured to allow the three beams to exit from the light guide mirror after traveling the same optical path.

[0004] In some embodiments, the deflector includes a substrate, a first grating deflector structure, and a second grating deflector structure. The substrate has a blue region, a green region, and a red region, wherein the green region separates the blue region and the red region. The first grating deflector structure is disposed on the blue region of the substrate. The second grating deflector structure is disposed on the red region of the substrate.

[0005] In some implementations, the spacing between the blue and green regions (or the green and red regions) is in the range of 100 nm to 2 mm.

[0006] In some embodiments, each of the first grating deflector structure and the second grating deflector structure includes a blazed grating structure, a stepped grating structure, a tilted grating structure, or a combination thereof, wherein the refractive index of each of the first grating deflector structure and the second grating deflector structure is in the range of 1.7 to 3.5.

[0007] In some embodiments, the first grating deflector structure includes a first supergrating structure. The first supergrating structure includes a first strip unit having a first width W1, a second strip unit having a second width W2, and a third strip unit having a third width W3, where W1 ≤ W2 ≤ W3. The first strip unit, the second strip unit, and the third strip unit are sequentially arranged along the outer surface of the blue region of the substrate to the inner surface of the blue region of the substrate.

[0008] In some embodiments, the first supergrating structure further includes a fourth strip unit having a fourth width W4 and a fifth strip unit having a fifth width W5, where W3 ≥ W4 ≥ W5. The fourth strip unit is adjacent to the third strip unit, and the fifth strip unit is adjacent to the fourth strip unit.

[0009] In some embodiments, the second grating deflector structure includes a second super grating structure. The second super grating structure includes a fourth strip unit having a fourth width W4, a fifth strip unit having a fifth width W5, and a sixth strip unit having a sixth width W6, where W4 ≤ W5 ≤ W6. The fourth, fifth, and sixth strip units are sequentially arranged along the outer surface of the red region of the substrate to the inner surface of the red region of the substrate.

[0010] In some embodiments, the second supergrating structure further includes a seventh strip unit with a seventh width W7 and an eighth strip unit with an eighth width W8, where W6 ≥ W7 ≥ W8. The seventh strip unit is adjacent to the sixth strip unit, and the eighth strip unit is adjacent to the seventh strip unit.

[0011] In some embodiments, the first grating deflector structure includes a first supergrating structure, which includes a plurality of elongated units with varying widths. The second grating deflector structure includes a second supergrating structure, which also includes a plurality of elongated units with varying widths. The number of elongated units in the first supergrating structure is the same as the number of elongated units in the second supergrating structure.

[0012] In some embodiments, the first grating deflector structure includes a first supergrating structure, which comprises a plurality of elongated units with varying widths. The second grating deflector structure includes a second supergrating structure, which also comprises a plurality of elongated units with varying widths. The number of elongated units in the first supergrating structure differs from the number of elongated units in the second supergrating structure.

[0013] In some embodiments, each of the first grating deflector structure and the second grating deflector structure includes a first cylindrical unit having a first diameter D1, a second cylindrical unit having a second diameter D2, and a third cylindrical unit having a third diameter D3, where D1 ≤ D2 ≤ D3. The first cylindrical unit, the second cylindrical unit, and the third cylindrical unit are sequentially arranged along the outer surface of the blue or red region of the substrate to the inner surface of the blue or red region of the substrate.

[0014] In some embodiments, each of the first grating deflector structure and the second grating deflector structure further includes a fourth cylindrical unit having a fourth diameter D4 and a fifth cylindrical unit having a fifth diameter D5, where D3 ≥ D4 ≥ D5. The fourth cylindrical unit is adjacent to the third cylindrical unit, and the fifth cylindrical unit is adjacent to the fourth cylindrical unit.

[0015] In some embodiments, the deflector includes a first quartz crystal having a first inclined plane and a first bottom surface, a second quartz crystal having a second inclined plane and a second bottom surface, and a third quartz crystal having a third inclined plane and a third bottom surface. The first bottom surface, the second bottom surface, and the third bottom surface are parallel to each other. A first angle θ1 is formed between the first inclined plane and the first bottom surface of the first quartz crystal, a second angle θ2 is formed between the second inclined plane and the second bottom surface of the second quartz crystal, and a third angle θ3 is formed between the third inclined plane and the third bottom surface of the third quartz crystal, where θ1 < θ2 < θ3. A first color separation filter is disposed on the first inclined plane, a second color separation filter is disposed on the second inclined plane, and a third color separation filter is disposed on the third inclined plane.

[0016] In some implementations, the second angle θ2 is 45 degrees. Attached Figure Description

[0017] The various aspects of the invention can be best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be understood that, in accordance with standard industry practice, the various features are not drawn to scale. In fact, the dimensions of the various features can be arbitrarily increased or decreased for clarity.

[0018] Figure 1 This is a schematic diagram of smart glasses according to some embodiments of the present invention.

[0019] Figure 2 for Figure 1 A partial top view of the smart glasses in the image.

[0020] Figure 3 This is a schematic diagram of an optical system according to some embodiments of the present invention.

[0021] Figure 4 for Figure 3A schematic diagram of the wavelengths of the three beams emitted from the projector after passing through the filter.

[0022] Figure 5A , Figure 5B and Figure 5C A schematic diagram of the original images of three separate beams.

[0023] Figure 5D This is a schematic diagram of an optical image of an overlaid color image.

[0024] Figure 6 for Figure 3 An enlarged view of the deflector in the image.

[0025] Figure 7 and Figure 8 For some embodiments of the content of the present invention Figure 6 A top view of the deflector in the image.

[0026] Figure 9A and Figure 9B They are respectively Figure 6 Enlarged views of the first and second supergrating structures in the image.

[0027] Figure 10A and Figure 10B They are respectively Figure 9A and Figure 9B Enlarged view of the changes in the first and second supergrating structures.

[0028] Figure 11 for Figure 8 A top view of the changing structure of the first supergrating structure of the deflector in the middle.

[0029] Figure 12 , Figure 13 and Figure 14 This is a cross-sectional schematic diagram of a deflector according to some variations of the present invention.

[0030] Figure 15 for Figure 3 A cross-sectional schematic diagram of a light guide lens with a grating coupler structure.

[0031] Figure 16 This is a schematic diagram of an optical system according to some embodiments of the present invention.

[0032] Figure 17A for Figure 16 An enlarged view of the structure of the first grating deflector in the image.

[0033] Figure 17B and Figure 17C for Figure 16 An enlarged view of the modified structure of the first grating deflector in the image.

[0034] Figure 18 for Figure 1 A partial top view of the smart glasses in the image.

[0035] Figure 19 This is a schematic diagram of an optical system according to some embodiments of the present invention.

[0036] Figure 20 for Figure 19 A partial view of the deflector in the image.

[0037] The symbols in the attached diagram are briefly explained as follows:

[0038] 100, 100A: Smart glasses; 110: Arm; 120, 120a: Optical elements; 121, 121A, 121B, 121C, 121D, 121E: Deflectors; 1212: Grating structure; 1212a: First grating deflector structure; 1212a1: Third-order grating structure; 1212a2: Blazed grating structure; 1212a3: Tilted grating structure; 1212am: First super-grating structure; 1212b: Second grating deflector structure; 1212bm: Second super-grating structure; 1214: Substrate; 122: Projector; 123: Polarizer; 124: Collimator; 125: Filter; 130: Grating coupler structure; 130a: First grating coupler structure ; 130b: Second grating coupler structure; 140: Light guide lens; 150: Light absorber; 172: Horizontal surface; 173: Vertical sidewall; 174: Horizontal surface; 175: Vertical sidewall; 176: Sloping sidewall; 177: Sloping sidewall; 178: Sloping sidewall; 179: Top surface; 300: Optical system; 500: Overlapping color image; 1600: Optical system; 1900: Optical system; 1910: Light absorber; 1922: Blue color filter; 1924: Green color filter; 1926: Red color filter; 1932, 1933, 1934, 1935, 1936, 1937: Quartz; L1-L1': Line; L2-L2': Line; S: Spacing; P B P R P GC Period; H B H R H GC : height; W BR W GR W RR Width; W1 B W2 B W3 B Wt-1 B Wt B Width; W1 RW2 R W3 R Wm-1 R Wm R : Width; U1 B U2 B U3 B Ut-1 B 、Ut B : Strip element / cylindrical element; U1 R U2 R U3 R Um-1 R Um R : Strip element / cylindrical element; P BL P BR P UL P UR : Point; BL: Blue light; GL: Green light; RL: Red light; BR: Blue area; GR: Green area; RR: Red area; θ1, θ2, θ3: Angle; θ B θ R Deflection angle; OS B OS G OS R : Bevel; BS B BS G BS R : Bottom surface; X, Y, Z: Directions. Detailed Implementation

[0039] The following invention provides many different implementations or embodiments for achieving various features of the invention. Specific embodiments of components and arrangements are described below to simplify the invention. These are, of course, merely embodiments and are not intended to be limiting. For example, in the following description, the formation of a first feature above or on a second feature may include an embodiment where the first and second features are formed in direct contact, or an embodiment where another feature may be formed between the first and second features so that the first and second features are not in direct contact. Furthermore, reference numerals or words may be repeated in different instances. The purpose of repetition is to simplify and clarify the description, not to define the relationships between the different implementations and configurations discussed.

[0040] It will be understood that although terms such as “first,” “second,” etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of the embodiments, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0041] In addition, spatial relative terms such as "below," "below," "lower than," "above," "above," and other similar terms are used here for the convenience of describing the relationship between one element or feature and another element or feature in the figure. Spatial relative terms cover not only the orientation depicted in the figure but also other orientations of the device during use or operation. The device may be oriented in other orientations (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein can be interpreted accordingly.

[0042] Additionally, when numbers or ranges are described as “approximately,” “about,” or other similar terms, this is to cover numbers described as falling within a reasonable range, as those skilled in the art will understand to be within + / - 10%. For example, the term “approximately 5nm” covers a size range from 4.5nm to 5.5nm.

[0043] The following describes several embodiments of the present invention with reference to the accompanying drawings. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details are not intended to limit the scope of the invention. That is, in some embodiments of the present invention, these practical details are not essential. Furthermore, for the sake of simplicity, some known and conventional structures and elements will be illustrated in the drawings in a simple schematic manner.

[0044] When a beam of light enters a light guide lens or glass through various optical elements, the RGB lights will have different optical path lengths. Therefore, the RGB light transmitted to the viewer's eye will be deflected. To solve the transmission and imaging problem caused by RGB light with different optical path lengths, multiple grating couplers and / or multiple optical elements can be used to achieve imaging along the same optical path. For example, three separate high-refractive-index glasses can be used to multiplex the three wavelengths of external light (e.g., the RGB wavelengths of light), and each glass has at least one grating coupler, ensuring that the RGB wavelengths are transmitted along the same optical path. However, three separate high-refractive-index glasses increase the thickness of the optical device and also increase the cost of manufacturing the optical elements.

[0045] The optical system of this invention adjusts the incident angles of three separate RGB images emitted from different positions, and then couples the RGB images with a deflector, a grating coupler, and a light guide lens. Furthermore, this invention provides an optical system incorporating a variation of the deflector structure. The deflector may comprise a meta-grating structure with multiple longitudinal units, a meta-grating structure with multiple cylindrical units, a step grating structure, a blazed grating structure, or a slanted grating structure. The deflector may also comprise three quartz cubes, each with a blue, green, and red color separation filter. The optical system of this invention reduces the thickness of optical elements and provides highly efficient RGB light (images). This invention can be applied to, for example, smart glasses for augmented reality (AR) and virtual reality (VR).

[0046] Figure 1 This is a schematic diagram of a smart glasses 100 according to some embodiments of the present invention. The smart glasses 100 includes an arm 110, an optical element 120, a grating coupler structure 130, and a light guide lens 140. The arm 110 and the optical element 120 extend along the Y direction, and the optical element 120 is disposed in the arm 110. The grating coupler structure 130 is disposed around the end of the arm 110. The light guide lens 140 extends along the X direction.

[0047] Figure 2 for Figure 1 A partial top view of the smart glasses 100. The optical element 120 comprises many components. For clarity, Figure 2 Only the deflector 121, which includes the grating structure 1212 and the substrate 1214, is shown. Detailed drawings of the optical element 120 will follow. Figure 3 As described in the text. A grating coupler structure 130 is disposed at the intersection of the end of the lens arm 110 and the end of the light guide lens 140. More specifically, the grating coupler structure 130 is disposed on the surface of the light guide lens 140.

[0048] Figure 3This is a schematic diagram of an optical system 300 according to some embodiments of the present invention. The optical system 300 includes a projector 122, a polarizer 123, a collimator 124, a filter 125, a deflector 121, a grating coupler structure 130, a light guide lens 140, and a light absorber 150. The projector 122 can emit three light beams with different wavelengths. Specifically, the three light beams extend along the Y direction. The light beams emitted by the projector 122 are not limited to three beams and can also be polychromatic light. The three beams can be blue light (BL), green light (GL), and red light (RL). It should be understood that the "three light beams" herein refers to blue light (BL), green light (GL), and red light (RL). The projector 122 is configured to overlay a color image 500 (see reference 500). Figure 5D Decoupled into three separate RGB images (please refer to...) Figures 5A to 5C In some embodiments, the projector 122 may be an organic light-emitting diode (OLED) projector, such that the blue light BL, green light GL, and red light RL may be broadband light. A polarizer 123 is disposed below the projector 122. Specifically, the polarizer 123 is disposed between the projector 122 and the deflector 121. The polarizer 123 is configured to filter out the transverse electric (TE) mode or transverse magnetic (TM) mode of the three beams emitted by the projector 122. A collimator 124 is disposed below the polarizer 123 and configured to limit the three angles of incidence of the three beams emitted by the projector 122. A filter 125 is disposed below the collimator 124 and configured to limit the wavelengths of the three beams emitted by the projector 122. In some embodiments, the filter 125 includes a narrow-band blue filter for blue light BL, a narrow-band green filter for green light GL, and a narrow-band red filter for red light RL. In some implementations, the order of polarizer 123, collimator 124 and filter 125 can be interchanged.

[0049] Figure 4 for Figure 3This diagram illustrates the wavelengths of the three light beams emitted from the projector 122 after passing through filter 125. Specifically, after the blue light BL, green light GL, and red light RL pass through filter 125, the wavelengths of the blue light BL, green light GL, and red light RL are narrowed. In some embodiments, after the blue light BL passes through filter 125, the wavelength of the blue light BL can be in the range of 430 nm to 491 nm, for example, about 440, 446, 457, 465, 473, or 488 nm. In some embodiments, after the green light GL passes through filter 125, the wavelength of the green light GL can be in the range of 510 nm to 581 nm, for example, about 515, 520, 532, 543, or 560 nm. In some embodiments, after the red light RL passes through filter 125, the wavelength of the red light RL can be in the range of 590 nm to 671 nm, for example, about 630, 633, 637, or 658 nm. It is understood that... Figure 3 The blue light BL, green light GL, and red light RL shown may also contain other colors of light. In some embodiments, the blue light BL, green light GL, and red light RL comprise three separate RGB images.

[0050] Refer again Figure 3 Deflector 121 is disposed below filter 125. Deflector 121 includes grating structure 1212 and substrate 1214. Grating structure 1212 is disposed on substrate 1214. Substrate 1214 includes a blue region BR, a green region GR, and a red region RR. The blue region BR and the red region RR are separated by the green region GR, as shown... Figure 3 As shown in the diagram, the grating structure 1212 includes a first grating deflector structure 1212a and a second grating deflector structure 1212b. The first grating deflector structure 1212a is disposed on the blue region BR of the substrate 1214, and the second grating deflector structure 1212b is disposed on the red region RR of the substrate 1214. In other words, there is no grating structure on the green region GR of the substrate 1214. It should be understood that, for clarity, Figure 2 and Figure 3 Only grating structure 1212 is shown. The detailed arrangement of grating structure 1212 will be discussed later. Figures 6 to 14 The discussion in the text discusses the variation of the grating structure 1212. Figures 17A to 17CThe following discussion is provided. In some embodiments, the refractive indices of the first grating deflector structure 1212a and the second grating deflector structure 1212b are each in the range of 1.7 to 3.5, for example, 1.8, 2.2, 2.6, 3.0, or 3.4. In some embodiments, the first grating deflector structure 1212a and the second grating deflector structure 1212b may be made of Al2O3, TiO2, Nb2O5, Si3N4, or Ta2O5. In some embodiments, the substrate 1214 may be a transparent substrate and may be made of glass, fused silica, sapphire, ceramic, polymer resin, or plastic. In some embodiments, the refractive index of the substrate 1214 may be in the range of 1.3 to 2.0, for example, 1.4, 1.5, 1.7, or 1.9.

[0051] exist Figure 3 In this configuration, a grating coupler structure 130 and a light guide lens 140 are disposed below a deflector 121. The grating coupler structure 130 includes a first grating coupler structure 130a and a second grating coupler structure 130b. The first grating coupler structure 130a and the second grating coupler structure 130b are connected to the light guide lens 140. The first grating coupler structure 130a is located below the deflector 121 and is configured to couple three light beams (e.g., blue light BL, green light GL, and red light RL) into the light guide lens 140, such that the three light beams travel the same optical path within the light guide lens 140. The light guide lens 140 is configured to transmit the three light beams. The deflector 121 is configured to change the three incident angles of the three light beams and focus the three light beams into the same area of ​​the first grating coupler structure 130a within the grating coupler structure 130. In detail, after the blue light BL passes through the deflector 121, it forms a blue light deflection angle θ on the first grating coupler structure 130a. B Similarly, after the red light RL passes through the deflector 121, it forms a red light deflection angle θ on the first grating coupler structure 130a. R The second grating coupler structure 130b of the grating coupler structure 130 is disposed on the light guide lens 140 and configured to allow the three beams to travel the same optical path before exiting the light guide lens 140. In some embodiments, the first grating coupler structure 130a and the second grating coupler structure 130b are made of the same material and have the same structure. In some embodiments, the light absorber 150 is disposed below the grating coupler structure 130. In some embodiments, the light absorber 150 is optional. The light absorber 150 is configured to absorb non-ideal light, such as 0th-order diffracted light of blue light BL, green light GL, and red light RL, or higher-order diffracted light (1st-order diffracted light is ideal light).

[0052] Figure 5A , Figure 5B and Figure 5CA schematic diagram of the original images of three separate light beams (blue light BL, green light GL, and red light RL). Figure 5D This is a schematic diagram of the optical image of the superimposed color image 500. For details, please refer to... Figure 3 After the three beams pass through deflector 121, their travel directions change, and they are then focused into the same region of the first grating coupler structure 130a of the grating coupler structure 130. Thus, the three beams are coupled into the light guide lens 140. Next, the three beams travel the same optical path along direction X within the light guide lens 140. Finally, the three beams are coupled out through the second grating coupler structure 130b of the grating coupler structure 130, causing the originally three separate beams to form a unified structure. Figure 5D The superimposed color image 500 is shown.

[0053] Figure 6 for Figure 3 An enlarged view of the deflector 121 in the diagram. Figure 6 The first grating deflector structure 1212am and the second grating deflector structure 1212bm in the grating structure 1212 are both super-grating structures. In other words, it can be... Figure 3 The first grating deflector structure 1212a in the middle is understood as Figure 6 The first supergrating structure in the 1212am will... Figure 3 The second grating deflector structure 1212b in the text is understood as Figure 6 The second super-grating structure in the text is 1212 lbm. It should be understood that, in this paper, "super-grating structure" refers to a grating structure where the units are different, and the width of the units increases or decreases systematically. For example... Figure 6 As shown, a plurality of first supergrating structures 1212am are disposed on the blue region BR of the substrate 1214. In some embodiments, the number of first supergrating structures 1212am is in the range of 125 to 8000, for example, about 200 to 4000. In some embodiments, the period P of the first supergrating structures 1212am is... B Within the range of 1000 to 8000 nm, for example, approximately 2000 to 5000 nm. In some embodiments, the height H of the first supergrating structure 1212 nm is... B Within the range of 20 to 2000 nm, for example, approximately 100 to 1000 nm. Similarly, a plurality of second supergrating structures 1212 µm are disposed on the red region RR of the substrate 1214. In some embodiments, the number of second supergrating structures 1212 µm is in the range of 125 to 8000, for example, approximately 200 to 4000. In some embodiments, the period P of the second supergrating structures 1212 µm is... RWithin the range of 1000 to 8000 nm, for example, approximately 2000 to 5000 nm. In some embodiments, the height H of the second supergrating structure is 1212 μm. R Within the range of 20 to 2000 nm, for example, approximately 100 to 1000 nm. In some embodiments, the width W of the blue region BR of substrate 1214 is... BR The width W of the green area GR GR And the width W of the red area RR RR Each of them is in the range of 1 to 8 mm. In some embodiments, the spacing S between the blue region BR and the green region GR, and the spacing S between the green region GR and the red region RR, are in the range of 100 nm to 2 mm, for example, about 10 to 200 μm.

[0054] Figure 7 and Figure 8 For some embodiments of the content of the present invention Figure 6 Top view of deflectors 121 and 121A. In detail, Figure 7 The cross-sectional view of deflector 121 along line L1-L1' is as follows Figure 6 , Figure 8 The cross-sectional view of line L2-L2' of deflector 121A in the middle is also... Figure 6 . refer to Figure 7 The first super-grating structure 1212am and the second super-grating structure 1212bm of the grating structure 1212 are elongated strips in shape. (Reference) Figure 8 The first super grating structure 1212am and the second super grating structure 1212bm of the grating structure 1212 are cylindrical in shape. Regardless of Figure 7 Deflector 121 or Figure 8 The deflectors 121A in the series all have the same cross-sectional schematic diagram, such as... Figure 6 As shown.

[0055] Figure 9A and Figure 9B They are respectively Figure 6 Enlarged images of the first supergrating structure 1212am and the second supergrating structure 1212bm. (Reference) Figure 9A The first supergrating structure 1212am includes a first width W1 B The first long strip unit U1 B Having a second width W2 B The second long strip unit U2 B It has a third width W3 B The third long strip unit U3 B Having a width of Wt-1 at the (t-1)th degree BThe (t-1)th strip unit Ut-1 B and has a width Wt of t B The t-th strip unit Ut B And W1 B ≤W2 B ≤W3 B ≤Wt-1 B ≤Wt B In other words, the multiple strip cells of the first supergrating structure 1212am are gradually varying in width. The first supergrating structure 1212am may contain t strip cells, and t≥4, for example, 5, 6, 8, or 10. Specifically, the period P of the first supergrating structure 1212am... B The quantity t defines the pitch. like Figure 9A As shown. Reference Figure 6 and Figure 9A The first long strip unit U1 B Second long strip unit U2 B and the third long strip unit U3 B The blue region BR of substrate 1214 is sequentially arranged from the outer surface to the inner surface of the blue region BR of substrate 1214 (in order to...). Figure 6 (See, set from left to right).

[0056] refer to Figure 9B The second supergrating structure 1212bm includes a first width W1 R The first long strip unit U1 R Having a second width W2 R The second long strip unit U2 R It has a third width W3 R The third long strip unit U3 R Having a width of Wm-1 (m-1)th degree R The (m-1)th strip unit Um-1 R and has a width of m, Wm R The m-th strip unit Um R And W1 R ≤W2 R ≤W3 R ≤Wm-1 R ≤Wm R In other words, the multiple strip cells of the second supergrating structure 1212bm are gradually varying in width. The second supergrating structure 1212bm may contain m strip cells, and m ≥ 4, for example, 5, 6, 8, or 10. Specifically, the period P of the second supergrating structure 1212bm... R And the quantity m defines the pitch. like Figure 9B As shown. Reference Figure 6 and Figure 9B The first long strip unit U1 R Second long strip unit U2 R and the third long strip unit U3 R The red region RR of substrate 1214 is sequentially arranged from the outer surface to the inner surface of the red region RR of substrate 1214 (in order to...). Figure 6 (See, set from right to left).

[0057] Figure 10A and Figure 10B They are respectively Figure 9A and Figure 9B Enlarged view of the modified structures of the first supergrating structure 1212am and the second supergrating structure 1212bm. Identical features are labeled with the same element symbols and will not be described again in the following figure. Figure 9A and Figure 10A The difference is that, Figure 10A The first supergrating structure 1212am in the middle also includes a width Wt+1 at the t+1th degree. B The (t+1)th strip unit Ut+1 B and has a width of Wt+2 at the t+2th degree. B The (t+2)th strip unit Ut+2 B Wt B ≥Wt+1 B ≥Wt+2 B The (t+1)th strip unit Ut+1 B Adjacent to the t-th strip unit Ut B And the (t+2)th strip unit Ut+2 B Adjacent to the (t+1)th strip unit Ut+1 B .

[0058] Figure 9B and Figure 10B The difference is that, Figure 10B The second supergrating structure 1212bm also includes a width Wm+1 of the (m+1)th degree. R The (m+1)th strip unit Um+1 R And Wm+2 with a width of m+2 R The (m+2)th strip unit Um+2 R Wm R ≥Wm+1 R ≥Wm+2 R The (m+1)th strip unit Um+1 R Adjacent to the m-th strip unit Um R And the (m+2)th strip unit Um+2 R Adjacent to the (m+1)th strip unit Um+1 R .

[0059] Figure 11 for Figure 8 A top view of the modified structure of the first supergrating structure 1212am of the deflector 121A. In detail, Figure 11 A cross-sectional schematic diagram (along direction X) of the first supergrating structure 1212am can be referenced. Figure 10A . Figure 11 The first supergrating structure 1212am is cylindrical, but when viewed from the XZ section, it has multiple circles. For example... Figure 11 As shown, the first supergrating structure 1212am includes a first diameter D1 B First cylindrical unit U1 B Having a second diameter D2 B The second cylindrical unit U2 B Having a third diameter D3 B The third cylindrical unit U3 B Having a diameter Dt-1 of the (t-1)th degree B The t-1th cylindrical element Ut-1 B and having a diameter Dt of the tth degree B The t-th cylindrical element Ut B And D1 B ≤D2 B ≤D3 B ≤Dt-1 B ≤Dt B . Figure 11 The first supergrating structure 1212am in the image also includes a diameter Dt+1 of the t+1th degree. B The (t+1)th cylindrical element Ut+1 B and having a diameter Dt+2 of the (t+2)th degree. B The (t+2)th cylindrical element Ut+2 B , where Dt B ≥Dt+1 B ≥Dt+2 B The (t+1)th cylindrical element Ut+1 B Adjacent to the t-th cylindrical unit Ut B And the (t+2)th cylindrical element Ut+2 B Adjacent to the (t+1)th cylindrical unit Ut+1 B Understandably, Figure 11 The arrangement and position of the first supergrating structure 1212am in the image can be similar to... Figure 8 The arrangement and position of the first supergrating structure 1212am are detailed below. Furthermore, variations of the second supergrating structure 1212bm can be... Figure 11 The first super grating structure in the 1212am is a horizontally symmetrical mirror structure.

[0060] See again Figure 6 , Figure 9A and Figure 9B All strip / cylindrical units U1 B U2 B U3 B Ut-1 B 、Ut B Having the same height H B All strip / cylindrical units U1 R U2 R U3 R Um-1 R Um R Having the same height H R In some implementations, such as Figure 6 As shown, the height H of the first supergrating structure 1212am B The height H is the same as that of the second supergrating structure, which is 1212bm. R In some implementations, the period P of the first supergrating structure 1212am B The period P is the same as that of the second supergrating structure, which is 1212 lbm. R ,like Figure 6 As shown.

[0061] Figure 12 , Figure 13 and Figure 14 This is a schematic cross-sectional view of deflectors 121B, 121C, and 121D according to some variations of the present invention. In some embodiments, such as Figure 12 The deflector 121B in the middle, the height H of the first supergrating structure 1212am B Unlike the second super grating structure with a height H of 1212bm R In some implementations, such as Figure 13 The deflector 121C and Figure 14 The deflector 121D in the middle, the period P of the first supergrating structure 1212am B Unlike the second supergrating structure with a period P of 1212 bps R In detail, in Figure 13 In the first supergrating structure 1212am, the number of stripe units is greater than that of the second supergrating structure 1212bm. Figure 14 In the first supergrating structure 1212am, the pitch between the long strip units is... The pitch between strip units smaller than 1212bm of the second super grating structure

[0062] Figure 15 for Figure 3A cross-sectional schematic diagram of a light guide lens 140 having a grating coupler structure 130. The grating coupler structure 130 includes a first grating coupler structure 130a and a second grating coupler structure 130b. Figure 15 The grating coupler structure 130 shown is a tilted grating coupler structure. Specifically, the grating coupler structure 130 starts from the lower left point P... BL P (bottom right) BR Top left point P UL and the upper right point P UR The position is defined accordingly. In some embodiments, the period P of the grating coupler structure 130 is... GC Within the range of 300nm to 500nm. In some embodiments, the height H of the grating coupler structure 130 is... GC The refractive index is in the range of 100 nm to 600 nm. In some embodiments, the refractive index of the grating coupler structure 130 is in the range of 1.7 to 3.5, for example, 1.8, 2.5, 2.9, or 3.4. In some embodiments, the refractive index of the light guide lens 140 is the same as or similar to the refractive index of the grating coupler structure 130.

[0063] Refer to Tables 1 to 3 below. Figure 3 , Figure 7 and Figure 15 The parameters are those of Experiment 1 under the condition that the first supergrating structure 1212am and the second supergrating structure 1212bm of the grating structure 1212 are elongated structures and the filter 125 is in TM mode.

[0064] Table 1

[0065]

[0066] Table 2

[0067]

[0068] Table 3

[0069]

[0070] In Experiment 1, as shown in Table 3, the total efficiency of blue light (BL) is 62.02%, the total efficiency of green light (GL) is 95.59%, and the total efficiency of red light (RL) is 62.02%. This embodiment demonstrates good RGB light efficiency.

[0071] Refer to Tables 4 to 6 below. Figure 3 , Figure 7 and Figure 15The parameters are those of Experiment 2 under the condition that the first super grating structure 1212am and the second super grating structure 1212bm of the grating structure 1212 are elongated structures and the filter 125 is in TE mode.

[0072] Table 4

[0073]

[0074] Table 5

[0075]

[0076] Table 6

[0077]

[0078] In Experiment 2, as shown in Table 6, the total efficiency of blue light (BL) is 47.10%, the total efficiency of green light (GL) is 86.42%, and the total efficiency of red light (RL) is 44.88%. This embodiment demonstrates good RGB light efficiency.

[0079] Refer to Tables 7 to 9 below. Figure 3 , Figure 8 and Figure 15 The parameters for Experiment 3 are as follows: the first supergrating structure 1212am and the second supergrating structure 1212bm of the grating structure 1212 are cylindrical, and the filter 125 is in TE mode.

[0080] Table 7

[0081]

[0082] Table 8

[0083]

[0084] Table 9

[0085]

[0086] In Experiment 3, as shown in Table 9, the total efficiency of blue light (BL) is 67.44%, the total efficiency of green light (GL) is 88.80%, and the total efficiency of red light (RL) is 67.44%. This embodiment demonstrates good RGB light efficiency.

[0087] Figure 16 This is a schematic diagram of an optical system 1600 according to some embodiments of the present invention. Figure 17A for Figure 16 An enlarged view of the first grating deflector structure 1212a in the diagram. Figure 17B and Figure 17C for Figure 16An enlarged view of the modified structure of the first grating deflector structure 1212a in the image. Figure 16 The first grating deflector structure 1212a in the grating structure 1212 can be a third-order grating structure 1212a1 (e.g. Figure 17A As shown), blazed grating structure 1212a2 (as shown) Figure 17B As shown), the tilted grating structure 1212a3 (as shown) Figure 17C (as shown) or a combination thereof.

[0088] Figure 16 The optical system 1600 and Figure 3 The difference between the optical systems 300 lies in the grating structure 1212. Specifically, Figure 3 The first grating deflector structure 1212a and the second grating deflector structure 1212b in the grating structure 1212 are supergrating structures. In some embodiments, Figure 16 The first grating deflector structure 1212a and the second grating deflector structure 1212b in the grating structure 1212 are third-order grating structures 1212a1 (reference). Figure 17A It is understandable that... Figure 16 The number of steps in the third-order grating structure is for illustrative purposes only and is not intended to limit the scope of this invention.

[0089] refer to Figure 17A The third-order grating structure 1212a1 includes multiple vertical sidewalls 173 and 175 and multiple horizontal surfaces 172 and 174. The horizontal surface 174 is adjoined to the vertical sidewalls 173 and 175. Figure 17A The grating structure in the image is a third-order grating structure 1212a1, but it can also be an n-order grating structure, where n ≥ 3. (See reference...) Figure 17B The blazed grating structure 1212a2 includes a sloping sidewall 176. The sloping sidewall 176 extends from the top to the bottom of the blazed grating structure 1212a2, and the width of the blazed grating structure 1212a2 gradually increases from the top to the bottom. (Reference) Figure 17C The tilted grating structure 1212a3 includes tilted sidewalls 177 and 178 and a top surface 179. The top surface 179 connects to the tilted sidewalls 177 and 178. Each tilted sidewall 177 and 178 of the tilted grating structure 1212a3 has a first tilt and a second tilt. In some embodiments, the first tilt is equal to the second tilt. In some embodiments, the first tilt is less than the second tilt. Furthermore, variations of the second grating deflector structure 1212b can be... Figures 17A to 17C The first grating deflector structure 1212a in the middle is a transversely symmetrical mirror structure.

[0090] Figure 18for Figure 1 A partial top view of the smart glasses in the image. Figure 2 Smart glasses 100 and Figure 18 The difference between the smart glasses 100A lies in the optical elements 120 and 120a. Detailed drawings of optical element 120a will be provided later. Figure 19 The same features are indicated by the same component symbols, and will not be described again in the following figure.

[0091] Figure 19 This is a schematic diagram of an optical system 1900 according to some embodiments of the present invention. The optical system 1900 includes a projector 122, a polarizer 123, a collimator 124, a filter 125, a deflector 121E, a light absorber 1910, a grating coupler structure 130, a light guide lens 140, and a light absorber 150. The deflector 121E includes a blue dichroic filter 1922 for blue light (BL), a green dichroic filter 1924 for green light (GL), and a red dichroic filter 1926 for red light (RL). The blue dichroic filter 1922, the green dichroic filter 1924, and the red dichroic filter 1926 can be understood as filter coatings for reflected light.

[0092] Figure 20 for Figure 19 A partial view of deflector 121E. Deflector 121E includes a first inclined plane OS. B and the first bottom surface BS B Quartz 1932, with a second inclined plane OS G Second bottom surface BS G Quartz 1934 and OS with a third bevel R and the third bottom surface BS R Quartz 1936. The first base of Quartz 1932 (BS) B The second base of Quartz 1934 (BS) G And the third base surface BS of Quartz 1936 R Parallel to each other. The first inclined plane OS of Quartz 1932. B With the first bottom surface BS B The first angle θ1 exists between them. The second inclined plane OS of quartz 1934... G With the second bottom surface BS G There is a second angle θ2 between them. The third inclined plane OS of quartz 1936 R With the third bottom surface BS R There is a third angle θ3 between them. In some embodiments, the second angle θ2 is 45 degrees, and θ1 < θ2 < θ3, such as... Figure 20 As shown in the image.

[0093] Still referencing Figure 20The blue color separation filter 1922 is set on the first inclined plane OS. B Above, the green color separation filter 1924 is set on the second inclined plane OS. G Above, the red color separation filter 1926 is set on the third inclined plane OS. R Above. It is understood that the blue color filter 1922 is aligned between quartz 1932 and quartz 1933 and combined into a blue deflector block. The green color filter 1924 is aligned between quartz 1934 and quartz 1935 and combined into a green deflector block. The red color filter 1926 is aligned between quartz 1936 and quartz 1937 and combined into a red deflector block. In some embodiments, the thickness of each of the blue, green, and red deflector blocks is in the range of 1 to 10 mm. In some embodiments, the blue deflector block has a transmittance greater than 90% for light with wavelengths less than 400 nm and a reflectance greater than 90% for light with wavelengths greater than 400 nm. In some embodiments, the green deflector block has a transmittance greater than 90% for light with wavelengths less than 500 nm and a reflectance greater than 90% for light with wavelengths greater than 500 nm. In some implementations, the red deflector square has a transmittance of greater than 90% for light with wavelengths less than 585 nm and a reflectance of greater than 90% for light with wavelengths greater than 585 nm. The blue, green, and red deflector squares are configured to adjust the three beams (three separate RGB images, see reference). Figures 5A to 5C The three incident angles of the image will be combined into a single color image (reference). Figure 5D Exposed to the first grating coupler structure 130a (reference) Figure 19 On the same area.

[0094] See again Figure 19 The light absorber 1910 is located next to (on the right side) the deflector 121E. The light absorber 1910 is configured to absorb light not absorbed by the optical element 120a (see reference). Figure 18 The beams reflected by the blue dichroic filter 1922, green dichroic filter 1924, and red dichroic filter 1926. The grating coupler structure 130, the light guide lens 140, and the light absorber 150 are disposed below the deflector 121E. Figure 19 (Bottom of the image). The three beams (blue BL, green GL, and red RL) emitted from the projector 122 are reflected by the blue color filter 1922, the green color filter 1924, and the red color filter 1926, respectively. Then, the incident angles of the three beams are changed and focused on the same area of ​​the first grating coupler structure 130a of the grating coupler structure 130.

[0095] The optical system of this invention adjusts the incident angles of three separate RGB images emitted from different positions, and then couples the RGB images with a deflector, a grating coupler, and a light guide mirror. Furthermore, this invention provides an optical system incorporating a variation of the deflector structure. The deflector may comprise a supergrating structure with multiple elongated units, a supergrating structure with multiple cylindrical units, an n-order echelle grating structure, a blazed grating structure, or a tilted grating structure. The deflector may also comprise three quartz cubes, each with a blue, green, and red color separation filter. The optical system of this invention reduces the thickness of optical components and provides highly efficient RGB light (images).

[0096] The above description is only a preferred embodiment of the present invention, but it is not intended to limit the scope of the present invention. Any person skilled in the art can make further improvements and changes on this basis without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the claims of this application.

Claims

1. An optical system, characterized in that, Include: A projector that emits three beams of light with different wavelengths; A deflector is located below the projector; A first grating coupler structure is located below the deflector. The deflector is configured to change the incident angle of the three beams and focus the three beams into the same area of ​​the first grating coupler structure, wherein the first grating coupler structure is a tilted grating structure. A light guide lens is connected to the first grating coupler structure and configured to transmit the three light beams. The first grating coupler structure is configured to couple the three light beams into the light guide lens, such that the three light beams travel the same optical path within the light guide lens. A polarizer, disposed between the projector and the deflector, and configured to simultaneously filter out the transverse electric field mode or transverse magnetic field mode of the three beams; and A second grating coupler structure is disposed on the light guide lens and configured such that the three beams exit from the light guide lens after traveling the same optical path.

2. The optical system according to claim 1, wherein, The deflector includes: A substrate having a blue region, a green region and a red region, wherein the green region separates the blue region and the red region; The first grating deflector structure is disposed on the blue area of ​​the substrate; as well as The second grating deflector structure is disposed on the red area of ​​the substrate.

3. The optical system according to claim 2, wherein, The spacing between the blue area and the green area is in the range of 100nm to 2mm.

4. The optical system according to claim 2, wherein, The second grating deflector structure includes a blazed grating structure, a stepped grating structure, a tilted grating structure, or a combination thereof, wherein the refractive index of each of the first grating deflector structure and the second grating deflector structure is in the range of 1.7 to 3.

5.

5. The optical system according to claim 2, wherein, The first grating deflector structure includes a first super grating structure, which comprises a first strip unit with a first width W1, a second strip unit with a second width W2, and a third strip unit with a third width W3, wherein W1≤W2≤W3. The first elongated unit, the second elongated unit, and the third elongated unit are arranged sequentially along the outer surface of the blue area of ​​the substrate to the inner surface of the blue area of ​​the substrate.

6. The optical system according to claim 5, wherein, The first supergrating structure also includes a fourth strip unit with a fourth width W4 and a fifth strip unit with a fifth width W5, where W3 ≥ W4 ≥ W5. The fourth long strip unit is adjacent to the third long strip unit, and the fifth long strip unit is adjacent to the fourth long strip unit.

7. The optical system according to claim 5, wherein, The second grating deflector structure includes a second super grating structure, which comprises a fourth strip unit with a fourth width W4, a fifth strip unit with a fifth width W5, and a sixth strip unit with a sixth width W6, wherein W4 ≤ W5 ≤ W6. The fourth, fifth, and sixth elongated units are arranged sequentially along the outer surface of the red region of the substrate to the inner surface of the red region of the substrate.

8. The optical system according to claim 7, wherein, The second supergrating structure also includes a seventh strip unit with a seventh width W7 and an eighth strip unit with an eighth width W8, where W6 ≥ W7 ≥ W8. The seventh long strip unit is adjacent to the sixth long strip unit, and the eighth long strip unit is adjacent to the seventh long strip unit.

9. The optical system according to claim 2, wherein, The first grating deflector structure includes a first super grating structure, which comprises multiple elongated units with gradually varying widths. The second grating deflector structure includes a second super grating structure, which comprises multiple elongated units with gradually varying widths, and The number of the plurality of elongated units in the first super grating structure is the same as the number of the plurality of elongated units in the second super grating structure.

10. The optical system according to claim 2, wherein, The first grating deflector structure includes a first super grating structure, which comprises multiple elongated units with gradually varying widths. The second grating deflector structure includes a second super grating structure, which comprises multiple elongated units with gradually varying widths, and The number of the plurality of elongated units in the first super grating structure is different from the number of the plurality of elongated units in the second super grating structure.

11. The optical system according to claim 2, wherein, Each of the first grating deflector structure and the second grating deflector structure includes a first cylindrical unit with a first diameter D1, a second cylindrical unit with a second diameter D2, and a third cylindrical unit with a third diameter D3, wherein D1 ≤ D2 ≤ D3. The first cylindrical unit, the second cylindrical unit, and the third cylindrical unit are sequentially arranged along the outer surface of the blue region or the red region of the substrate to the inner surface of the blue region or the red region of the substrate.

12. The optical system according to claim 11, wherein, Each of the first grating deflector structure and the second grating deflector structure further includes a fourth cylindrical unit having a fourth diameter D4 and a fifth cylindrical unit having a fifth diameter D5, where D3 ≥ D4 ≥ D5. The fourth cylindrical unit is adjacent to the third cylindrical unit, and the fifth cylindrical unit is adjacent to the fourth cylindrical unit.

13. The optical system according to claim 1, wherein, The deflector comprises a first quartz crystal having a first inclined surface and a first bottom surface, a second quartz crystal having a second inclined surface and a second bottom surface, and a third quartz crystal having a third inclined surface and a third bottom surface, wherein the first bottom surface, the second bottom surface, and the third bottom surface are parallel to each other. In the first quartz, there is a first angle θ1 between the first inclined surface and the first bottom surface; in the second quartz, there is a second angle θ2 between the second inclined surface and the second bottom surface; and in the third quartz, there is a third angle θ3 between the third inclined surface and the third bottom surface, where θ1 < θ2 < θ3. The first color separation filter is disposed on the first inclined surface, the second color separation filter is disposed on the second inclined surface, and the third color separation filter is disposed on the third inclined surface.

14. The optical system according to claim 13, wherein, The second angle θ2 is 45 degrees.

Images