Embedding film for waveguide combiners

Abstract

A waveguide combiner comprising a first substrate, a second substrate, and a wavelength-selective film, wherein the wavelength-selective film is positioned between the first substrate and the second substrate, and the wavelength-selective film is operable to reflect red light, refract and transmit blue light, and refract and transmit green light.

Description

[Technical Field]

[0001]

[0001] Embodiments of the present disclosure generally relate to waveguide combiners. More specifically, embodiments described herein provide a film-embedded waveguide combiner. [Background technology]

[0002] Description of related technologies

[0002] Virtual reality is generally considered to be a computer-generated simulated environment in which the user has an apparent physical presence. Virtual reality experiences are generated in 3D and can be viewed with a head-mounted display (HMD) (for example, glasses or other wearable display devices having a near-eye display panel as a lens for displaying a virtual reality environment that replaces the actual environment).

[0003]

[0003] However, augmented reality allows a user to see the surrounding environment through the display lenses of glasses or other HMD devices, but also to see images of virtual objects that are generated for display and appear as part of the environment. Augmented reality may include any type of input (e.g., voice input and haptic input) and virtual images, graphics, and videos that enhance or extend the environment experienced by the user. As a new technology, augmented reality has many challenges and design constraints.

[0004]

[0004] One such challenge is to display a virtual image superimposed on the surrounding environment. Waveguide combiners are used to assist in image superposition. The generated light is incoupled into the waveguide combiner, propagates through an extended waveguide combiner, is outcoupled from this extended waveguide combiner, and is overlaid on the surrounding environment. The light is incoupled and outcoupled with the extended waveguide combiner using a surface relief diffraction grating.

[0005]

[0005] However, conventional surface relief gratings suffer from significant color non-uniformity. One reason for this color non-uniformity is that the interaction density with the grating surface is significantly lower for longer wavelengths than for shorter wavelengths due to the dispersion of diffraction angles in the propagation angle within the underlying substrate. Furthermore, shallow surface relief gratings have higher diffraction efficiency for shorter wavelengths compared to longer wavelengths, which exacerbates the variation in interaction density between wavelengths.

[0006]

[0006] Current solutions to the aforementioned problems include incorporating a semi-reflective layer into the waveguide combiner and / or coupling a low refractive index substrate to the back of a higher refractive index substrate. However, because the semi-reflective layer does not exhibit strong angular and wavelength selectivity, it does not fully address the problem of color non-uniformity in waveguide combiners designed to support multiple display color channels. Furthermore, the transition between angles at which propagation is possible and not possible in a low refractive index substrate coupled to a higher refractive index substrate is very sharp in the user's field of view, which results in undesirable non-uniformity in the viewed image.

[0007]

[0007] Therefore, what is needed in the art is an improved structure for waveguide combiners. [Overview of the project]

[0008]

[0008] Specific embodiments of this specification provide a waveguide combiner comprising a first substrate, a second substrate, and a wavelength-selective film. The first substrate includes a structural surface, a first film surface opposite the structural surface, a first refractive index (RI), and a surface relief structure disposed on the structural surface. The second substrate includes a second film surface, a second RI, and a reflective surface opposite the second film surface. The wavelength-selective film lies between the first and second film surfaces. The wavelength-selective film has a film RI, which is lower than the first and second RIs. The film thickness of the wavelength-selective film is approximately 1 nanometer (nm) to approximately 10 micrometers (μm). The wavelength-selective film is operable to reflect red light, refract blue light through the wavelength-selective film, transmit blue light to the first and second substrates, refract green light through the wavelength-selective film, and transmit green light to the first and second substrates.

[0009]

[0009] Certain embodiments of this specification provide a waveguide combiner comprising a first substrate, a second substrate, a wavelength-selective film, and a local thickness adjustment layer (LTAL). The first substrate includes a structural surface, a first film surface facing the structural surface, and a surface relief structure disposed on the structural surface. The second substrate includes a second film surface and a reflective surface opposite the second film surface. The wavelength-selective film is located between the first and second film surfaces, and the local thickness adjustment layer (LTAL) is disposed on the reflective surface. The LTAL has a target substrate thickness distribution that varies across the reflective surface.

[0010]

[0010] Certain embodiments of this specification provide a method for projecting an image with improved color uniformity. The method includes in-coupling light into a waveguide combiner. The light includes at least three input wavelengths, the at least three input wavelengths include blue light, green light, and red light, and the waveguide combiner includes a structural surface, a first substrate, a second substrate including a reflective surface, and a wavelength selective film disposed between the first substrate and the second substrate. The method further includes reflecting red light off the structural surface with the wavelength selective film, refracting blue light through the wavelength selective film and transmitting the blue light through the first substrate and the second substrate, and refracting green light through the wavelength selective film and transmitting the green light through the first substrate and the second substrate. Thereafter, the method includes out-coupling light from the waveguide combiner.

[0011]

[0011] To enable a more detailed understanding of the above-described features of the present disclosure, a more specific description of the present disclosure, briefly summarized above, can be obtained by referring to the embodiments. Some of those embodiments are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate exemplary embodiments and, thus, should not be considered as limiting the scope of the present disclosure, and other equally valid embodiments may be permitted.

Brief Description of the Drawings

[0012] [Figure 1] It is a cross-sectional view of a waveguide combiner according to an embodiment described in this specification. [Figure 2A-2C] It is a cross-sectional view of a waveguide combiner according to an embodiment described in this specification. [Figure 3] It is a cross-sectional view of a waveguide combiner according to an embodiment described in this specification. [Figure 4] It is a perspective front view of a waveguide combiner according to an embodiment described in this specification.

Modes for Carrying Out the Invention

[0013]

[0016] For ease of understanding, the same reference numerals have been used to indicate identical elements common to the figures where possible. It is intended that elements and features of one embodiment can be advantageously incorporated into other embodiments without further description.

[0014]

[0017] Embodiments of this disclosure generally relate to waveguide combiners. More specifically, embodiments described herein provide film-embedded waveguide combiners to address the challenges of color non-uniformity in conventional waveguides.

[0015]

[0018] Figure 1 is a cross-sectional view of a waveguide combiner 100 that facilitates the projection of images with improved color uniformity. The waveguide combiner 100 includes at least one of a first substrate 102, a second substrate 104, and a wavelength-selective film 106. The first substrate 102 includes a structural surface 112 and a first film surface 114 facing the structural surface 112. The second substrate 104 includes a second film surface 116 and a reflective surface 118 facing the second film surface 116.

[0016]

[0019] The first substrate 102 and / or the second substrate 104 can be any substrate used in the art and may be opaque or transparent to light of a selected wavelength, depending on the use of the first substrate 102 and / or the second substrate 104 as substrates for waveguide combiners. The choice of substrate may include, but is not limited to, amorphous dielectrics, non-amorphous dielectrics, crystalline dielectrics, polymers, or combinations thereof, any suitable material substrate. In some embodiments, the first substrate 102 and / or the second substrate 104 include, but are not limited to, silicon-containing materials, silicon and oxygen-containing compounds, germanium-containing materials, indium and phosphorus-containing compounds, gallium and arsenic-containing compounds, gallium and nitrogen-containing compounds, carbon-containing materials, silicon and carbon-containing compounds, silicon, carbon, and oxygen-containing compounds, silicon and nitrogen-containing compounds, silicon, oxygen, and nitrogen-containing compounds, niobium and oxygen-containing compounds, lithium, niobium, and oxygen-containing compounds, aluminum and oxygen-containing compounds, indium, tin, and oxygen-containing compounds, titanium and oxygen-containing compounds, lanthanum and oxygen-containing compounds, gadolinium and oxygen-containing compounds, zinc and oxygen-containing compounds, yttrium and oxygen-containing compounds, tungsten and oxygen-containing compounds, potassium and oxygen-containing compounds, phosphorus and oxygen-containing compounds, barium and oxygen-containing compounds, sodium and oxygen-containing compounds, or combinations thereof. In other embodiments that can be combined with other embodiments described herein, the first substrate 102 and / or the second substrate 104 include an oxide containing one or more of the following materials: gadolinium, silicon, sodium, barium, potassium, tungsten, phosphorus, zinc, calcium, titanium, tantalum, niobium, lanthanum, zirconium, lithium, or yttrium.Exemplary materials for substrates 102 and / or 104 include silicon (Si), silicon monoxide (SiO), silicon dioxide (SiO2), silicon carbide (SiC), fused silica, diamond, quartz germanium (Ge), silicon germanium (SiGe), indium phosphide (InP), gallium arsenide (GaAs), gallium nitride (GaN), sapphire, sapphire (Al2O3), lithium niobate (LiNbO3), and indium tin oxide. This includes (ITO), lanthanum oxide (La2O3), gadolinium oxide (Gd2O5), zinc oxide (ZnO), yttrium oxide (Y2O3), tungsten oxide (WO3), titanium oxide (TiO2), zirconium oxide (ZrO3), sodium oxide (Na2O), niobium oxide (Nb2O5), barium oxide (BaO), potassium oxide (K2O), phosphorus pentoxide (P2O5), calcium oxide (CaO), or combinations thereof. In some embodiments, the first substrate 102 and the second substrate 104 are formed from the same material(s). In some other embodiments, the first substrate 102 and the second substrate 104 are formed from different materials(s).

[0017]

[0020] In some embodiments, the first substrate 102 comprises a first material having a first refractive index (RI). In some embodiments, the first RI is about 1.3 to about 3.5 at visible light wavelengths (e.g., about 380 nm to about 700 nm, e.g., about 635 nm). For example, in some embodiments, the first RI is about 1.4 to about 3.4, or about 1.5 to about 3.3, or about 1.6 to about 3.2, or about 1.7 to about 3.1, or about 1.8 to about 3.0, or about 1.9 to about 2.9, or about 2.0 to about 2.8, or about 2.1 to about 2.7, or about 2.2 to about 2.6, or 2.3 to about 2.5 at visible light wavelengths. In some embodiments, the first RI is about 1.5 to about 2.7 at visible light wavelengths.

[0018]

[0021] In some embodiments, the second substrate 104 includes a second material having a second radioisotope (RI). In some embodiments, the second RI is greater than the first RI at visible wavelengths. In some embodiments, the second RI is greater than the first RI minus about 0.2 to about 0.5 at visible wavelengths. For example, in some embodiments, the second RI is greater than the first RI minus about 0.3 or about 0.4 at visible wavelengths.

[0019]

[0022] The first substrate 102 has a first thickness d from the structural surface 112 to the first film surface 114 facing the structural surface 112. sub1 The second substrate 104 has a second thickness d from the second film surface 116 to the reflective surface 118 opposite to the second film surface 116. sub2 It has a first thickness d. In some embodiments, the first thickness d sub1 and the second thickness d sub2 The thickness of the first thickness d is about 25 micrometers (μm) or greater, either independently or collectively. For example, in some embodiments, the first thickness d sub1 and the second thickness d sub2 The thickness is approximately 50 μm or more, independently or collectively. In some embodiments, the first thickness d sub1 and the second thickness d sub2 These particles are approximately 75 μm or larger, either independently or collectively.

[0020]

[0023] The waveguide combiner 100 includes a surface relief structure (SRS) 108 disposed on the structural surface 112 of the first substrate 102. The waveguide combiner 100 includes one or more of the incoupling region (ICR) 130, pupil dilation element (PE) 132, or outcoupling region (OCR) 134 of the SRS 108. In certain embodiments, the SRS 108 may have different dimensions in at least two of the ICR 130, PE 132, and OCR 134. In certain embodiments, the SRS 108 may have the same or similar dimensions in at least two of the ICR 130, PE 132, and OCR 134.

[0021]

[0024] In some embodiments, SRS108 and the first substrate 102 are formed of different materials (s). For example, in some embodiments, SRS108 includes, but is not limited to, one or more oxides, carbides, or nitrides of silicon, aluminum, zirconium, tin, tantalum, zirconium, barium, titanium, hafnium, lithium, lanthanum, cadmium, niobium, or combinations thereof. Exemplary materials for SRS108 include silicon carbide, silicon oxycarbide, titanium oxide, silicon oxide, vanadium oxide, aluminum oxide, zinc oxide doped with aluminum, indium tin oxide, tin oxide, zinc oxide, tantalum oxide, silicon nitride, zirconium oxide, niobium oxide, cadmium stannate, silicon oxynitride, barium titanate, diamond-like carbon, hafnium oxide, lithium niobate, silicon carbonitride, silver, gold, cadmium selenide, mercury telluride, zinc selenide, silver-indium-gallium-sulfur, silver-indium-sulfur, indium phosphide, gallium phosphide, lead sulfide, lead selenide, zinc sulfide, molybdenum sulfide, tungsten sulfide, or combinations thereof.

[0022]

[0025] [[ID=⑤]]The wavelength selective film 106 is disposed between the first film surface 114 and the second film surface 116. In some embodiments, the wavelength selective film 106 contacts the first film surface 114 and the second film surface 116. The wavelength selective film 106 has a film thickness d from the first film surface 114 to the second film surface 116. film In some embodiments, the film thickness d film is from about 1 nm to about 10 μm. For example, in some embodiments, the film thickness d film is from about 1 nm to about 9 μm, or from about 1 nm to about 8 μm, or from about 1 nm to about 7 μm, or from about 1 nm to about 6 μm, or from about 1 nm to about 5 μm, or from about 1 nm to about 4 μm, or from about 1 nm to about 3 μm, or from about 1 nm to about 1 μm, or is about 0.5 μm. In some embodiments, the film thickness d film is from about 25 nm to about 4 μm, for example, from about 50 nm to about 3 μm.

[0023]

[0026] The wavelength-selective film 106 has a film RI. In some embodiments, the film RI is lower than the first and second RIs. In some embodiments, the film RI is about 1.1, about 1.2, or about 1.3 times smaller than the first RI at visible light wavelengths. For example, in certain embodiments, the film RI is about 1.4 times smaller than the first RI at visible light wavelengths. In some embodiments, the film RI is lower than the first RI.

[0024]

[0027] The wavelength-selective film 106 includes, but is not limited to, amorphous dielectrics, non-amorphous dielectrics, crystalline dielectrics, silicon dioxide, metals, alloys, polymers, organic resist materials, nanoparticle-doped resist materials, optical adhesives, or combinations thereof. For example, the wavelength-selective film 106 includes, but is not limited to, silicon dioxide (SiO2), titanium monoxide (TiO), titanium dioxide (TiO2), niobium monoxide (NbO), niobium dioxide (NbO2), niobium pentoxide (Nb2O5), hafnium dioxide (HfO2), tantalum pentoxide (Ta2O5), dilantanedititanium heptaoxide (La2Ti2O7), aluminum oxide (Al2O3), zirconium dioxide (ZrO2), magnesium difluoride (MgF2), cerium trifluoride (CeF3), silicon nitride (Si3N4), or combinations thereof.

[0025]

[0028] The light coupled to the waveguide combiner 100 includes three input wavelengths, namely blue light 107, green light 109, and red light 111. The light is incoupled by ICR 130. The blue light 107 has a wavelength of approximately 380 nm to approximately 495 nm, the green light 109 has a wavelength of approximately 495 nm to approximately 590 nm, and the red light 111 has a wavelength of approximately 590 nm to approximately 750 nm.

[0026]

[0029] The wavelength-selective film 106 is operable to reflect red light 111. The red light 111 is reflected from the wavelength-selective film 106 to the structural surface 112 of the first substrate 102. The wavelength-selective film 106 is operable to refract blue light 107 from the structural surface 112 through the wavelength-selective film 106 and further transmit the blue light 107 to the reflective surface 118 of the second substrate 104. The blue light 107 reflected from the reflective surface 118 of the second substrate 104 is refracted through the wavelength-selective film 106 and transmitted to the structural surface 112 of the first substrate 102. The wavelength-selective film 106 is operable to refract green light 109 from the structural surface 112 through the wavelength-selective film 106 and transmit the green light 109 to the reflective surface 118 of the second substrate 104. The green light 109 reflected from the reflective surface 118 of the second substrate 104 is refracted through the wavelength-selective film 106 and transmitted to the structural surface 112 of the first substrate 102.

[0027]

[0030] The wavelength-selective film 106 described herein is placed between a first substrate 102 and a second substrate 104 and provides reflection of red light 111 having a wavelength with a shorter bounce interval, and diffraction and transmission of blue light 107 and green light 109 having a larger bounce interval. The reflection of red light 111 and the transmission of blue light 107 and green light 109 that undergo TIR through the waveguide combiner 100 provide a bounce interval (d) between red light 111, blue light 107, and green light 109 in the OCR 134. bounce ) is obtained, and an image from OCR134 with improved color uniformity is projected. As described herein, the first RI and first thickness d of the first substrate 102 sub1 , as well as the second RI and second thickness d of the second substrate 104 sub2 The film RI and film thickness d of the wavelength-selective film 106 for the wavelength-selective film 106. film As a result, d for projecting improved color uniformity and improved image bounce You can obtain this.

[0028]

[0031] Figure 2A is a cross-sectional view of a waveguide combiner 200 that facilitates the projection of images with improved color uniformity. The waveguide combiner 200 includes a first substrate 102, a second substrate 104, and a wavelength-selective film 106. The first substrate 102 includes a structural surface 112 and a first film surface opposite the structural surface 112. The second substrate 104 includes a second film surface 116 and a reflective surface 118 facing the second film surface 116.

[0029]

[0032] The waveguide combiner 200 includes an SRS 108 disposed on the structural surface 112 of the first substrate 102. The waveguide combiner 200 includes one or more of the ICR 130, PE 132, or OCR 134 of the SRS 108.

[0030]

[0033] To prevent undesirable reflections from the external environment of the waveguide combiner 200, an anti-reflective coating 202 is placed on the reflective surface 118 of the second substrate 104. The anti-reflective coating 202 comprises one or more layers. Each layer of the anti-reflective coating 202 includes, but is not limited to, amorphous dielectrics, non-amorphous dielectrics, crystalline dielectrics, silicon oxide, metals, alloys, polymers, organic resist materials, nanoparticle-doped resist materials, optical adhesives, or combinations thereof. For example, each layer of the anti-reflective coating 202 includes, but is not limited to, SiO2, titanium monoxide (TiO), titanium dioxide (TiO2), niobium monoxide (NbO), niobium dioxide (NbO2), niobium pentoxide (Nb2O5), hafnium dioxide (HfO2), tantalum pentoxide (Ta2O5), dilantanedititanium heptoxide (La2Ti2O7), aluminum oxide (Al2O3), zirconium dioxide (ZrO2), magnesium difluoride (MgF2), cerium trifluoride (CeF3), silicon nitride (Si3N4), or combinations thereof. In some embodiments, one or more layers of the anti-reflective coating 202 are formed from the same material. In some embodiments, one or more layers of the anti-reflective coating 202 are formed from different materials. In some embodiments, one or more layers of the anti-reflective coating 202 have a thickness collectively between about 10 nm and about 1000 nm, for example, between about 100 nm and about 900 nm, or between about 200 nm and about 800 nm, or between about 300 nm and about 700 nm, or about 550 nm.

[0031]

[0034] Figure 2B is a cross-sectional view of a waveguide combiner 225 that facilitates the projection of images with improved color uniformity. The waveguide combiner 225 includes a first substrate 102, a second substrate 104, and a wavelength-selective film 106. The first substrate 102 includes a structural surface 112 and a first film surface opposite the structural surface 112. The second substrate 104 includes a second film surface 116 and a reflective surface 118 facing the second film surface 116.

[0032]

[0035] The waveguide combiner 225 includes an SRS 108 disposed on the structural surface 112 of the first substrate 102. The waveguide combiner 225 includes one or more of the ICR 130, PE 132, or OCR 134 of the SRS 108.

[0033]

[0036] A localized thickness adjustment layer (LTAL) 204 is placed on a reflective surface (e.g., the reflective surface 118 of the second substrate 104) to achieve a distribution or variation in the thickness of the target substrate. In other embodiments, the LTAL 204 is placed on the uppermost substrate surface. In some embodiments, the LTAL 204 is placed between the structural surface 112 of the first substrate 102 and the SRS 108. Generally, the LTAL 204 can function to achieve a target local thickness variation (LTV) or target total thickness variation (TTV) across the reflective surface 118, which can be beneficial in optimizing the performance of the waveguide combiner 225. As light travels through the waveguide combiner 225 by total internal reflection, variations in the thickness of various layers alter the light propagation path. This can adversely affect the projected image quality, potentially causing field distortion, image blur, and loss of sharpness. Therefore, controlling the thickness of the waveguide combiner 225 at the target location can reduce or eliminate such image quality defects.

[0034]

[0037] LTAL204 may have a localized thickness adjustment layer thickness in the range of about 0.1 nm to about 5 nm, for example, between about 0.5 nm and about 4 nm, or between about 1 nm and about 3 nm. In some embodiments, LTAL(204) may have a thickness greater than about 5 nm. Generally, LTAL204 may be sized and modified to provide a target thickness distribution for optimal device performance and to mitigate thickness deviations that may adversely affect performance metrics such as efficiency, uniformity, and sharpness (MTF). In some embodiments, LTAL has a refractive index within about ±0.2 of the refractive index of the adjacent substrate at visible light wavelengths. Generally, LTAL204 can be sized to provide an optimal thickness distribution for the device.

[0035]

[0038] In some embodiments, LTAL204 is formed from any suitable material, provided that LTAL204 can adequately transmit light of a desired wavelength or wavelength range and have desired light propagation characteristics. In some embodiments, LTAL204 is formed from amorphous dielectrics, non-amorphous dielectrics, crystalline dielectrics, silicon oxide, polymers, or combinations thereof. In some embodiments, LTAL204 is formed from a transparent material. In some embodiments, LTAL204 is formed from at least one of silicon (Si), silicon dioxide (SiO2), fused silica, quartz, silicon carbide (SiC), germanium (Ge), silicon germanium (SiGe), indium phosphide (InP), gallium arsenide (GaAs), gallium nitride (GaN), sapphire, or combinations thereof.

[0036]

[0039] The anti-reflective coating 202 is placed on a reflective surface (e.g., the reflective surface 118 of the second substrate 104 on LTAL 204). The anti-reflective coating 202 comprises one or more layers. Each layer of the anti-reflective coating 202 includes, but is not limited to, amorphous dielectrics, non-amorphous dielectrics, crystalline dielectrics, silicon dioxide, metals, alloys, polymers, organic resist materials, nanoparticle-doped resist materials, optical adhesives, or combinations thereof. For example, each layer of the anti-reflective coating 202 includes, but is not limited to, SiO2, titanium monoxide (TiO), titanium dioxide (TiO2), niobium monoxide (NbO), niobium dioxide (NbO2), niobium pentoxide (Nb2O5), hafnium dioxide (HfO2), tantalum pentoxide (Ta2O5), dilantanedititanium heptoxide (La 2 This includes Ti2O7), aluminum oxide (Al2O3), zirconium dioxide (ZrO2), magnesium difluoride (MgF2), cerium trifluoride (CeF3), silicon nitride (Si3N4), or combinations thereof. In some embodiments, one or more layers of the anti-reflective coating 202 are formed from the same material. In some embodiments, one or more layers of the anti-reflective coating 202 are formed from different materials.

[0037]

[0040] Figure 2C is a cross-sectional view of a waveguide combiner 250 that facilitates the projection of images with improved color uniformity. The waveguide combiner 250 includes a first substrate 102, a second substrate 104, a third substrate 208, a wavelength-selective film 106, and a second wavelength-selective film 206. The first substrate 102 includes a structural surface 112 and a first film surface opposite the structural surface 112. The second substrate 104 includes a second film surface 116 and a reflective surface 118 opposite the second film surface 116. The third substrate 208 includes a third film surface 120 and a third reflective surface 122 opposite the third film surface 120.

[0038]

[0041] The third substrate 208 comprises a third material having a third radioisotope (RI). In some embodiments, the third RI is greater than the second RI at visible light wavelengths. In some embodiments, the third RI is greater than the second RI minus about 0.2 to about 0.5 at visible light wavelengths. For example, in some embodiments, the third RI is greater than the second RI minus about 0.3 or about 0.4 at visible light wavelengths.

[0039]

[0042] The third material includes, but is not limited to, amorphous dielectrics, non-amorphous dielectrics, crystalline dielectrics, silicon oxide, polymers, or combinations thereof. For example, the third material includes, but is not limited to, silicon-containing materials, silicon and oxygen-containing compounds, germanium-containing materials, indium and phosphide-containing compounds, gallium and arsenic-containing compounds, gallium and nitrogen-containing compounds, carbon-containing materials, silicon and carbon-containing compounds, silicon, carbon, and oxygen-containing compounds, silicon and nitrogen-containing compounds, silicon, oxygen, and nitrogen-containing compounds, niobium and oxygen-containing compounds, as well as lithium, niobium, and oxygen-containing compounds, aluminum and oxygen-containing compounds, indium, tin, and oxygen-containing compounds, titanium and oxygen-containing compounds, lanthanum and oxygen-containing compounds, gadolinium and oxygen-containing compounds, zinc and oxygen-containing compounds, yttrium and oxygen-containing compounds, tungsten and oxygen-containing compounds, potassium and oxygen-containing compounds, phosphorus and oxygen-containing compounds, barium and oxygen-containing compounds, sodium and oxygen-containing compounds, or combinations thereof. In other embodiments that can be combined with other embodiments described herein, the first substrate 102 and / or the second substrate 104 include an oxide containing one or more of the following materials: gadolinium, silicon, sodium, barium, potassium, tungsten, phosphorus, zinc, calcium, titanium, tantalum, niobium, lanthanum, zirconium, lithium, or yttrium.Exemplary materials for substrates 102 and / or 104 include silicon (Si), silicon monoxide (SiO), silicon dioxide (SiO2), silicon carbide (SiC), fused silica, diamond, quartz germanium (Ge), silicon germanium (SiGe), indium phosphide (InP), gallium arsenide (GaAs), gallium nitride (GaN), sapphire, sapphire (Al2O3), lithium niobate (LiNbO3), and indium tin oxide. This includes (ITO), lanthanum oxide (La2O3), gadolinium oxide (Gd2O5), zinc oxide (ZnO), yttrium oxide (Y2O3), tungsten oxide (WO3), titanium oxide (TiO2), zirconium oxide (ZrO3), sodium oxide (Na2O), niobium oxide (Nb2O5), barium oxide (BaO), potassium oxide (K2O), phosphorus pentoxide (P2O5), calcium oxide (CaO), or combinations thereof. In some embodiments, the first substrate 102, the second substrate 104, and / or the third substrate 208 are formed from the same material. In some embodiments, the first substrate 102, the second substrate 104, and / or the third substrate 208 are formed from different materials.

[0040]

[0043] The third substrate 208 has a third thickness d from the third film surface 120 to the third reflective surface 122 opposite to the third film surface 120. sub3 It has a third thickness d. In some embodiments, sub3 This is approximately 25 μm or more. In some embodiments, the third thickness d sub3 This is approximately 50 μm or more. In some embodiments, the third thickness d sub3 It is approximately 75 μm or larger.

[0041]

[0044] The waveguide combiner 250 includes an SRS 108 disposed on the structural surface 112 of the first substrate 102. The waveguide combiner 250 includes one or more of the ICR 130, PE 132, or OCR 134 of the SRS 108.

[0042]

[0045] The second wavelength-selective film 206 is positioned between the third film surface 120 of the third substrate 208 and the reflective surface 118 of the second substrate 104. In some embodiments, the second wavelength-selective film 206 is in contact with the third film surface 120 and the reflective surface 118. The wavelength-selective film 206 extends from the third film surface 120 of the third substrate 208 to the reflective surface 118 of the second substrate 104, with a second film thickness d film2 It has a second film thickness d film2 The thickness is approximately 1 nm to approximately 10 μm. For example, in some embodiments, the film thickness d film2 The thickness is approximately 1 nm to 9 μm, or approximately 1 nm to 8 μm, or approximately 1 nm to 7 μm, or approximately 1 nm to 6 μm, or approximately 1 nm to 5 μm, or approximately 1 nm to 4 μm, or approximately 1 nm to 3 μm, or approximately 1 nm to 1 μm, or approximately 0.5 μm. In some embodiments, the film thickness d film2 This range is approximately 25 nm to 4 μm, for example, approximately 50 nm to 3 μm.

[0043]

[0046] The second wavelength-selective film 206 has a second film RI. In some embodiments, the second film RI is smaller than the second and third RIs. In other embodiments, the second film RI is about 1.1, about 1.2, or about 1.3 times smaller than the second RI at visible light wavelengths. For example, in certain embodiments, the second film RI is about 1.4 times smaller than the second RI at visible light wavelengths. The second wavelength-selective film 206 includes, but is not limited to, amorphous dielectrics, non-amorphous dielectrics, crystalline dielectrics, silicon oxide, metals, alloys, polymers, organic resist materials, nanoparticle-doped resist materials, optical adhesives, or combinations thereof. For example, the second wavelength-selective film 206 includes, but is not limited to, SiO2, titanium monoxide (TiO), titanium dioxide (TiO2), niobium monoxide (NbO), niobium dioxide (NbO2), niobium pentoxide (Nb2O5), hafnium dioxide (HfO2), tantalum pentoxide (Ta2O5), dilantanedititanium heptaoxide (La2Ti2O7), aluminum oxide (Al2O3), zirconium dioxide (ZrO2), magnesium difluoride (MgF2), cerium trifluoride (CeF3), silicon nitride (Si3N4), or combinations thereof.

[0044]

[0047] The second wavelength-selective film 206 is operable to reflect green light 109. The green light 109 is reflected from the second wavelength-selective film 206 to the second film surface 116 of the second substrate 104. The wavelength-selective film 106 is operable to refract the green light 109 from the second film surface 116 of the second substrate 104 through the wavelength-selective film 106, thereby transmitting the green light 109 to the structural surface 112 of the first substrate 102. The second wavelength-selective film 206 is operable to refract blue light 107 from the second film surface 116 of the second substrate 104 through the second wavelength-selective film 206, thereby transmitting the blue light 107 to the third reflective surface 122 of the third substrate 208. Blue light 107 from the third reflective surface 122 of the third substrate 208 is refracted through the second wavelength-selective film 206 and transmitted to the second film surface 116 of the second substrate 104. The wavelength-selective film 106 is operable to refract the blue light 107 from the second film surface 116 of the second substrate 104 through the wavelength-selective film 106 so that the blue light 107 is transmitted to the structural surface 112 of the first substrate 102.

[0045]

[0048] The second wavelength-selective film 206 described herein is located between the second substrate 104 and the third substrate 208 and results in the reflection of green light 109 having a shorter bounce interval, as well as the diffraction and transmission of blue light 107 having a larger bounce interval. The reflection of green light 109 and the transmission of blue light 107 that undergoes TIR through waveguide combiner 100 result in a bounce interval d between red light 111, blue light 107, and green light 109 in OCR 134. bounce This reduces the color uniformity of the OCR134, resulting in projected images with improved color uniformity. The second film RI and second film thickness d of the second wavelength-selective film 206 film2 , the second RI and the second thickness d of the second substrate 104 sub2 , the thickness d of the wavelength-selective film 106 film , as well as the first RI and first thickness d of the first substrate 102 described herein. sub1 The third substrate 208 has a third RI and a third thickness d sub3This is the bounce interval d for projecting an image with improved color uniformity. bounce It brings about.

[0046]

[0049] Figure 3 is a cross-sectional view of a waveguide combiner 300 that facilitates the projection of images with improved color uniformity. The waveguide combiner 300 includes at least one of a first substrate 102, a second substrate 104, and a wavelength-selective multilayer film 302. The first substrate 102 includes a structural surface 112 and a first film surface 114 facing the structural surface 112. The second substrate 104 includes a second film surface 116 and a reflective surface 118 facing the second film surface 116.

[0047]

[0050] The waveguide combiner 300 includes an SRS 108 disposed on the structural surface 112 of the first substrate 102. The waveguide combiner 300 includes one or more of the ICR 130, PE 132, or OCR 134 of the SRS 108.

[0048]

[0051] The wavelength-selective multilayer film 302 is positioned between the first film surface 114 and the second film surface 116. In one embodiment, the wavelength-selective multilayer film 302 is in contact with the first film surface 114 and the second film surface 116. The wavelength-selective multilayer film 302 has a multilayer film thickness d from the first film surface 114 to the second film surface 116. multi It has. In some embodiments, multilayer film thickness d multi It is greater than about 1 nm and about 10 μm. For example, in some embodiments, the film thickness is multi The thickness is approximately 1 nm to approximately 9 μm, or approximately 1 nm to approximately 8 μm, or approximately 1 nm to approximately 7 μm, or approximately 1 nm to approximately 6 μm, or approximately 1 nm to approximately 5 μm, or approximately 1 nm to approximately 4 μm, or approximately 1 nm to approximately 3 μm, or approximately 1 nm to approximately 1 μm, or greater than approximately 0.5 μm. In some embodiments, the film thickness d multi This range is approximately 25 nm to 4 μm, for example, approximately 50 nm to 3 μm.

[0049]

[0052] The wavelength-selective multilayer film 302 includes at least two sublayers. For example, the at least two sublayers may be sublayer 302a, sublayer 302b, sublayer 302c, and sublayer 302d. In certain embodiments, the multilayer film 302 includes at least three layers, or at least four layers, or at least five layers, or at least six layers, or at least seven layers, or at least eight layers, or at least nine layers, or at least ten layers, or between ten and 100 layers, or more.

[0050]

[0053] The wavelength-selective multilayer film 302 has a multilayer refractive index. In some embodiments, the wavelength-selective multilayer film 302 includes at least two sublayers, the at least two sublayers including at least one material having a multilayer refractive index (RI) less than about 1.1, about 1.2, or about 1.3 than a first RI at visible light wavelengths. For example, in certain embodiments, the multilayer RI is less than about 1.4 than the refractive index of the first RI at visible light wavelengths. In other embodiments, the refractive index of the multilayer film may be the total effective refractive index of the combined sublayers, which is about 1.1, about 1.2, about 1.3, or about 1.4 lower than the first refractive index at visible light wavelengths. In yet another embodiment, the refractive index of the multilayer film is 0.1, about 1.2, about 1.3, or about 1.4 lower than the refractive index of a substrate layer adjacent to the wavelength-selective multilayer film 302.

[0051]

[0054] At least two sublayers of the wavelength-selective multilayer film 302 include, but are not limited to, amorphous dielectrics, non-amorphous dielectrics, crystalline dielectrics, silicon dioxide, metals, alloys, polymers, organic resist materials, nanoparticle-doped resist materials, optical adhesives, or combinations thereof. For example, at least two sublayers of the wavelength-selective multilayer film 302 may include, but are not limited to, SiO2, titanium monoxide (TiO), titanium dioxide (TiO2), niobium monoxide (NbO), niobium dioxide (NbO2), niobium pentoxide (Nb2O5), hafnium dioxide (HfO2), tantalum pentoxide (Ta2O5), dilantanedititanium heptaoxide (La2Ti2O7), aluminum oxide (Al2O3), zirconium dioxide (ZrO2), magnesium difluoride (MgF2), cerium trifluoride (CeF3), silicon nitride, or combinations thereof. In some embodiments, at least two sublayers of the wavelength-selective multilayer film 302 are formed from the same material. In some embodiments, at least two sublayers of the wavelength-selective multilayer film 302 are formed from different materials.

[0052]

[0055] The wavelength-selective multilayer film 302 is operable to reflect red light 111. The red light 111 is reflected from the wavelength-selective multilayer film 302 to the structural surface 112 of the first substrate 102. The wavelength-selective multilayer film 302 is operable to refract blue light 107 from the structural surface 112 through the wavelength-selective multilayer film 302 and further transmit the blue light 107 to the reflective surface 118 of the second substrate 104. The blue light 107 reflected from the reflective surface 118 of the second substrate 104 is refracted through the wavelength-selective multilayer film 302 and transmitted to the structural surface 112 of the first substrate 102. The wavelength-selective multilayer film 302 is operable to refract green light 109 from the structural surface 112 through the wavelength-selective multilayer film 302 and further transmit the green light 109 to the reflective surface 118 of the second substrate 104. The green light 109 reflected from the reflective surface 118 of the second substrate 104 is refracted through the wavelength-selective multilayer film 302 and transmitted to the structural surface 112 of the first substrate 102.

[0053]

[0056] The wavelength-selective multilayer film 302 described herein provides reflection of red light 111 having a wavelength with a shorter bounce interval, and diffraction and transmission of blue light 107 and green light 109 having a larger bounce interval. Reflection of red light 111 and transmission of blue light 107 and green light 109 receiving TIR through waveguide combiner 300 provides a bounce interval d between red light 111, blue light 107, and green light 109 in OCR 134. bounce This results in a projected image with improved color uniformity from OCR134. The first RI and first thickness d of the first substrate 102 described herein. sub1 The thickness of the second substrate 104, and the second RI and second thickness d sub2 The wavelength-selective film 106, with its film RI and film thickness, consequently projects an image with improved color uniformity, and the bounce interval d bounce This leads to a decrease.

[0054]

[0057] Figure 4 is a perspective front view of the waveguide combiner 400. Waveguide combiner 400 should be understood to represent any of the waveguide combiners in Figures 1, 2A, 2B, 2C, and 3. Waveguide combiner 400 includes SRS108. SRS108 may be located on, below, or above the structural surface 112 of the first substrate 102, or it may be located within the first substrate 102. SRS108 is a nanostructure and has submicron limit dimensions, e.g., a width of less than 1 micrometer. Regions or grids of SRS108 correspond to one or more of ICR130, PE132, or OCR134.

[0055]

[0058] While the above description applies to embodiments of the present disclosure, other embodiments and further embodiments of the present disclosure can be devised without departing from the basic scope of the present disclosure, and the scope of the present disclosure is defined by the following claims.

Claims

1. Waveguide combiner, The first substrate, A structural surface and a first film surface facing the structural surface, The first refractive index (RI), and Surface relief structure placed on the aforementioned structural surface A first substrate including, The second substrate, Second film surface, Second RI, Reflective surface opposite the second film surface A second substrate including, A wavelength-selective film between the first film surface and the second film surface, wherein the film RI is smaller than the first RI and the second RI. Equipped with, The wavelength-selective film, It reflects red light, The blue light is refracted through the wavelength-selective film, and the blue light is transmitted to the first substrate and the second substrate. The wavelength-selective film refracts the green light, and transmits the green light to the first substrate and the second substrate. A waveguide combiner capable of operating in this manner.

2. The wavelength-selective film, The wavelength-selective film reflects the red light to the structural surface of the first substrate. A waveguide combiner according to claim 1, which is capable of operating in this manner.

3. The wavelength-selective film, The blue light is refracted from the structural surface through the wavelength-selective film to the reflective surface of the second substrate. The blue light is refracted from the reflective surface through the wavelength-selective film to the structural surface of the first substrate. A waveguide combiner according to claim 2, which is capable of operating in this manner.

4. The wavelength-selective film, The green light is refracted from the structural surface through the wavelength-selective film to the reflective surface of the second substrate. The green light is refracted from the reflective surface through the wavelength-selective film to the structural surface of the first substrate. A waveguide combiner according to claim 3, which is capable of operating in this manner.

5. The blue light has wavelengths ranging from approximately 380 nanometers (nm) to approximately 495 nm. The aforementioned green light has a wavelength of approximately 495 nm to approximately 590 nm. The aforementioned red light has a wavelength of approximately 590 nm to approximately 750 nm. Waveguide combiner according to claim 4.

6. The waveguide combiner according to claim 1, wherein the red light, the blue light, and the green light contact the surface relief structure in the outcoupling region (OCR) of the surface relief structure.

7. Waveguide combiner according to claim 1, wherein the first substrate and the second substrate are formed of at least one of the following: silicon-containing material, silicon and oxygen-containing compound, germanium-containing material, indium and phosphorus-containing compound, gallium and arsenic-containing compound, gallium and nitrogen-containing compound, carbon-containing material, silicon and carbon-containing compound, silicon, carbon and oxygen-containing compound, silicon and nitrogen-containing compound, silicon, oxygen and nitrogen-containing compound, niobium and oxygen-containing compound, and lithium, niobium and oxygen-containing compound, aluminum and oxygen-containing compound, indium, tin and oxygen-containing compound, titanium and oxygen-containing compound, lanthanum and oxygen-containing compound, gadolinium and oxygen-containing compound, zinc and oxygen-containing compound, yttrium and oxygen-containing compound, tungsten and oxygen-containing compound, potassium and oxygen-containing compound, phosphorus and oxygen-containing compound, barium and oxygen-containing compound, or sodium and oxygen-containing compound.

8. The first substrate and the second substrate are made of at least one of silicon (Si), silicon monoxide (SiO), silicon dioxide (SiO ２ ), silicon carbide (SiC), fused silica, diamond, quartz germanium (Ge), silicon germanium (SiGe), indium phosphide (InP), gallium arsenide (GaAs), gallium nitride (GaN), sapphire, sapphire (Al ２ O ３ ), lithium niobate (LiNbO ３ ), indium tin oxide (ITO), lanthanum oxide (La ２ O ３ ), gadolinium oxide (Gd ２ O ５ ), zinc oxide (ZnO), yttrium oxide (Y ２ O ３ ), tungsten oxide (WO ３ ), titanium oxide (TiO ２ ), zirconium oxide (ZrO ３ ), sodium oxide (Na ２ O), niobium oxide (Nb ２ O ５ ), barium oxide (BaO), potassium oxide (K ２ O), phosphorus pentoxide (P ２ O ５ ), or calcium oxide (CaO). The waveguide combiner according to claim 7.

9. The waveguide combiner according to claim 1, wherein the wavelength-selective film is formed of at least one of amorphous dielectrics, non-amorphous dielectrics, crystalline dielectrics, silicon oxide, metals, alloys, polymers, organic resist materials, nanoparticle-doped resist materials, or optical adhesives.

10. The wavelength-selective film is made of silicon dioxide (SiO ２ ), titanium monoxide (TiO), titanium dioxide (TiO) ２ ), niobium monoxide (NbO), niobium dioxide (NbO ２ ), niobium pentoxide (Nb ２ O ５ ), hafnium dioxide (HfO ２ ), tantalum pentoxide (Ta ２ O ５ ), dilanthane dititanium heptoxide (La ２ Ti ２ O ７ ), aluminum oxide (Al ２ O ３ ), zirconium dioxide (ZrO ２ ), magnesium difluoride (MgF ２ ), cerium trifluoride (CeF ３ ), or silicon nitride (Si ３ N ４ The waveguide combiner according to claim 9, which is formed of at least one of the following:

11. Waveguide combiner, The first substrate, structured surface, The first film surface facing the structural surface, and Surface relief structure placed on the aforementioned structural surface A first substrate including, The second substrate, The second film surface, and Reflective surface opposite the second film surface A second substrate including, A wavelength-selective film between the first film surface and the second film surface, A local thickness adjustment layer (LTAL) disposed on the reflective surface, the local thickness adjustment layer (LTAL) having a target substrate thickness distribution that changes on the reflective surface A waveguide combiner equipped with the following features.

12. The waveguide combiner according to claim 11, wherein the surface relief structure is organized into at least one of an outcoupling region (OCR), an incoupling region (ICR), and a pupil dilation element (PE).

13. The waveguide combiner according to claim 11, wherein the wavelength-selective film is in contact with the first film surface and the second film surface.

14. The waveguide combiner according to claim 11, wherein the LTAL is in contact with the reflective surface.

15. The first substrate and the second substrate are composed of silicon (Si), silicon monoxide (SiO), and silicon dioxide (SiO ２ ), silicon carbide (SiC), fused silica, diamond, quartz germanium (Ge), silicon germanium (SiGe), indium phosphide (InP), gallium arsenide (GaAs), gallium nitride (GaN), sapphire, sapphire (Al ２ Oc), lithium niobate (LiNbO) ３ ), indium tin oxide (ITO), lanthanum oxide (La ２ O ３ ), gadolinium oxide (Gd ２ O ５ ), zinc oxide (ZnO), yttrium oxide (Y ２ O ３ ), tungsten oxide (WO ３ ), titanium oxide (TiO ２ ), zirconium oxide (ZrO ３ ), sodium oxide (Na ２ O), niobium oxide (Nb ２ O ５ ), barium oxide (BaO), potassium oxide (K ２ O), phosphorus pentoxide (P ２ O ５ The waveguide combiner according to claim 11, which is formed of at least one of ), or calcium oxide (CaO).

16. The wavelength-selective film is made of silicon dioxide (SiO ２ ), titanium monoxide (TiO), titanium dioxide (TiO) ２ ), niobium monoxide (NbO), niobium dioxide (NbO ２ ), niobium pentoxide (Nb ２ O ５ ), hafnium dioxide (HfO ２ ), tantalum pentoxide (Ta ２ O ５ ), dilanthane dititanium heptoxide (La ２ Ti ２ O ７ ), aluminum oxide (Al ２ O ３ ), zirconium dioxide (ZrO ２ ), magnesium difluoride (MgF ２ ), cerium trifluoride (CeF ３ ), or silicon nitride (Si ３ N ４ A waveguide combiner according to claim 11, which is formed of at least one of the following:

17. The aforementioned LTAL is silicon (Si), silicon dioxide (SiO ２ A waveguide combiner according to claim 11, formed of at least one of the following: fused silica, quartz, silicon carbide (SiC), germanium (Ge), silicon germanium (SiGe), indium phosphide (InP), gallium arsenide (GaAs), gallium nitride (GaN), sapphire, or a combination thereof.

18. The waveguide combiner according to claim 11, further comprising an anti-reflective coating disposed on the reflective surface.

19. The antireflection coating is made of at least one of silicon dioxide (SiO ２ ), titanium monoxide (TiO), titanium dioxide (TiO ２ ), niobium monoxide (NbO), niobium dioxide (NbO ２ ), niobium pentoxide (Nb ２ O ５ ), hafnium dioxide (HfO ２ ), tantalum pentoxide (Ta ２ O ５ ), lanthanum dititanium heptoxide (La ２ Ti ２ O ７ ), aluminum oxide (Al ２ O ３ ), zirconium dioxide (ZrO ２ ), magnesium difluoride (MgF ２ ), cerium trifluoride (CeF ３ ), or silicon nitride (Si ３ N ４ ), the waveguide combiner according to claim 17.

20. A method for projecting images with improved color uniformity, This involves incoupling light into a waveguide combiner. The light comprises at least three input wavelengths, and the at least three input wavelengths comprise blue light, green light, and red light. The waveguide combiner, Structural surface and, The first substrate and A second substrate including a reflective surface, A wavelength-selective film disposed between the first substrate and the second substrate, This includes incoupling light in a waveguide combiner, The red light is reflected onto the surface of the structure by the wavelength-selective film, The blue light is refracted through the wavelength-selective film, and the blue light is transmitted to the first substrate and the second substrate. The green light is refracted through the wavelength-selective film, and the green light is transmitted to the first substrate and the second substrate. Outcoupling the light from the waveguide combiner A method that includes this.

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