Compact lighting system with improved optical performance

Abstract

The optical device may include a first polarization selection surface and a second polarization selection surface, each polarization selection surface configured to reflect incident light of a first polarization and transmit incident light of a second polarization orthogonal to the first polarization, the first polarization selection surface is disposed between the first optical input surface and the second optical input surface at a first angle alpha relative to an optical axis of the device, and the second polarization selection surface is disposed between the first optical input surface and the second optical input surface at a second angle beta relative to the optical axis.

Description

Technical Field

[0001] The present disclosure relates to the field of near eye display systems such as head mounted displays. More specifically, the present disclosure relates to a compact projection system designed for near eye displays (NEDs). Background Art

[0002] Consumer demand for improved human-machine interfaces has led to increased interest in high-quality image head-mounted displays (HMDs) or near-eye displays, commonly referred to as smart glasses. These devices can provide virtual reality (VR) or augmented reality (AR) experiences, thereby enhancing the way users interact with digital content and their surroundings.

[0003] Consumers seek better image quality, immersive experience, and greater comfort when using HMDs. Consumers expect displays with high resolution, vivid colors, and minimal distortion to create a realistic and enjoyable viewing experience. In addition, since users often wear these devices for long periods of time, comfort is a key factor. Consumers expect lightweight, sleek designs that are less obtrusive and more convenient to wear in various scenarios. Smaller devices also provide improved portability, making them easier to carry and use in different environments. Therefore, there is a growing demand for higher-performance but smaller and more compact HMDs.

[0004] The key element of a near-eye display system is the projector. In the case of HMDs and NEDs, the image projector is a device that generates visual content and projects it onto an intermediate medium (i.e., a light guide) for delivery to the eye. The goal is to provide the user with an image or video perception, often with an illusion of depth or three-dimensionality.

[0005] The technology behind projectors for HMDs and NEDs includes a reflective spatial light modulator (SLM), such as Liquid Crystal on Silicon (LCoS). Conventionally, SLM-based projectors require a relatively large volume to transmit light from a light source such as an LED to the SLM and to transmit the modulated light to the pupil of a light guide. This relatively large volume hinders the stated goal of compactness of HMDs.

[0006] Therefore, innovative compact lighting systems are needed. Summary of the invention

[0007] The present disclosure is directed to coupling light from a projection system using a polarizing beam splitter (PBS) structure with a novel design, thereby ensuring enhanced optical performance while minimizing the system size. The inventive concept is particularly beneficial in applications involving reflective spatial light modulators (SLMs), such as liquid crystal on silicon (LCoS) technology, where the telecentricity of the optical system and the normal incidence of light on the SLM are important for proper modulation of the light and image formation. Through the innovative design of the PBS structure and the incorporation of additional optical components such as prisms, waveguides, mirrors, and polarization rotation devices, the disclosed invention is directed to addressing the challenges associated with conventional bulky optical systems in NEDs, paving the way for more compact, efficient, and high-performance optical solutions in near-eye display technology.

[0008] The optical device may include a first polarization selective surface and a second polarization selective surface, each polarization selective surface being configured to reflect incident light of a first polarization and transmit incident light of a second polarization orthogonal to the first polarization, the first polarization selective surface being disposed between the first optical input surface and the second optical input surface at a first angle α relative to an optical axis of the device, and the second polarization selective surface being disposed between the first optical input surface and the second optical input surface at a second angle β relative to the optical axis, wherein β is approximately equal to -α.

[0009] The accompanying drawings included in the specification and forming a part of the specification illustrate various example systems, methods, etc. of various example embodiments of various aspects of the present invention. It will be appreciated that the element boundaries (e.g., boxes, groups of boxes, or other shapes) shown in the figures represent an example of boundaries. It will be appreciated by those of ordinary skill in the art that an element can be designed as multiple elements, or multiple elements can be designed as one element. An element shown as an internal component of another element can be implemented as an external component, and conversely, an element shown as an external component of another element can be implemented as an internal component. In addition, the elements may not be drawn to scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A schematic diagram showing a conventional illumination system used in a near-eye display (NED) is shown.

[0011] Figure 2A An exemplary lighting system including the novel device having two PBS surfaces is shown.

[0012] Figure 2B and Figure 2C Shows Figure 2A Schematic and exploded views of the novel device.

[0013] Figure 2D A system comprising the novel device and a LOE or waveguide is shown.

[0014] Figure 3A Another exemplary lighting system including the novel apparatus is shown.

[0015] Figure 3B Shows Figure 3A perspective of the system.

[0016] Figure 3C and Figure 3D Shows Figure 3A Optical simulation of a system showing light filling for two different angular fields.

[0017] Figure 4 Another exemplary lighting system including the novel apparatus is shown.

[0018] Figure 5 Another exemplary lighting system including the novel apparatus is shown. DETAILED DESCRIPTION

[0019] Figure 1 Schematic diagram of a conventional illumination system 1 used in a near-eye display (NED) is shown. The system 1 includes a reflective spatial light modulator (SLM) 6, such as liquid crystal on silicon (LCoS), and a prism or polarization beam splitter (PBS) 5 located close to the SLM 6. Typically, as Figure 1 As depicted, light used for illumination is directed to the vicinity of the exit pupil P of the system 1. Figure 1 As shown, the pupil P near the PBS 5 generally operates most efficiently in a telecentric optical setup, meaning that the chief ray from each angular field strikes the SLM 6 at a normal angle. In this context, normal corresponds to an angle of 90° + / - 10% (i.e., 81° to 99°) relative to the surface being illuminated.

[0020] Typically, a light source 7, such as an LED or multiple LEDs, is positioned in front of some optical devices, and the light from this source is directed by a PBS prism 5 into a telecentric optical system that sharpens the LCoS image. For simplicity, Figure 1 Only two rays emitted from the light source 7 are shown, which are bent by the lens 71 before entering the PBS prism 5. In one embodiment, the LED light is S polarized and is reflected by the surface 3 of the PBS 5. The ray 100, which is the chief ray, strikes the SLM 6 at a normal angle (for illustration purposes, the chief ray such as the ray 100 is slightly offset from the normal angle so as not to overlap itself in the illustration) and is reflected by the PBS 5 towards the center of the pupil P. Figure 1In the embodiment shown, the optical lens of system 1 is represented by a simple lens 11, which is placed in a 2F system (which means that the distance from the pupil P to the lens 11 in the y direction is equal to the distance from the lens 11 to the plane of the SLM 6). A ray 101 that is not the chief ray is reflected differently around the ray 100, after which its polarization is changed by the SLM 6 and it reaches the pupil P through the PBS 5.

[0021] In a system such as Figure 1 system 1 of, the PBS 5 needs to be large enough (in both the x and y dimensions) so that substantially all the light from the LED 7 can illuminate the surface 3 without being reflected from any other surface of the PBS 5. This requirement for a large PBS 5 can lead to the optical system 1 being undesirably large in volume, which may also potentially impede its performance.

[0022] Figure 2A A new system 10 is shown, which includes a novel structure 15 having two PBS surfaces 13 and 14. The structure 15 can have a thickness (y dimension) that is significantly smaller compared to the Figure 1 PBS cube 5 of, which makes the system 10 smaller than the Figure 1 system 1 of.

[0023] Figure 2B A schematic diagram of the novel structure 15 is shown.

[0024] The optical device 15 includes a device body 151 having a first optical input surface 152 provided at a first end of the device body 151 and a second optical input surface 153 provided at a second end of the device body opposite the first end. The device body 151 also has a first optical output surface 154 provided at a first side of the device body and a second optical output surface 155 provided at a second side of the device body opposite the first side. The device 15 has an optical axis y that is orthogonal to the first optical output surface 154 and the second optical output surface 155.

[0025] The optical device 15 further includes a first polarization selection surface 13 that reflects incident light of a first polarization (e.g., S or P polarization) and transmits incident light of a second polarization (e.g., P or S polarization) that is orthogonal to the first polarization. The first polarization selection surface 13 is disposed between the first optical input surface 152 and the second optical input surface 153 at a first angle α with respect to the optical axis y such that light entering the optical device 15 through the first optical input surface 152 is incident on the first polarization selection surface 13, and the incident light of the first polarization (e.g., S or P polarization) is reflected through the second optical output surface 155 out of the optical device 15.

[0026] The optical device 15 further includes a second polarization selection surface 14 that reflects incident light of a first polarization (e.g., S or P polarization) and transmits incident light of a second polarization (e.g., P or S polarization) orthogonal to the first polarization. The second polarization selection surface 14 is disposed between the first optical input surface 152 and the second optical input surface 153 at a second angle β relative to the optical axis y, so that light entering the optical device 15 through the second optical input surface 153 is incident on the second polarization selection surface 14, and the incident light of the first polarization (e.g., S or P polarization) is reflected through the second optical output surface 155 to the outside of the optical device 15.

[0027] exist Figure 2A and Figure 2B In the optical device 15 (as well as other optical devices 15a and 15b disclosed herein), β is approximately equal to -α to maintain relative symmetry. In this context, "approximately" means within 10%. That is, the difference between β and -α is + / -10%. The angle α can be in the range of 30° to 75° relative to the optical axis y, and the angle β can be in the range of -30° to -75° relative to the optical axis y. In a specific example, the first angle α is 45° relative to the optical axis y, and the second angle β is -45° relative to the optical axis y. In another specific example, the first angle α is 60° relative to the optical axis y, and the second angle β is 60° relative to the optical axis y-.

[0028] Figure 2C An exploded view of a device body 151 is shown. The device body 151 may be formed by adjoining at least three optical parts 156, 157a, 157b, each of which is made of an optically transparent material.

[0029] One or more polarization selective coatings or foils 158a, 158b may be disposed between at least three portions 156, 157a, 157b. That is, the adjoining surfaces of the optical portions 156, 157a, 157b may be coated with one or more polarization selective coatings configured to reflect incident light of a first polarization (e.g., S or P polarization) and transmit incident light of a second polarization (e.g., P or S polarization) orthogonal to the first polarization, such that the adjoining surfaces form a first polarization selective surface 13 and a second polarization selective surface 14 when abutting.

[0030] Return to Figure 2A, the system 10 comprises two light sources 7, 8, each with its own set of optics 71, 81. The SLM 6 is arranged adjacent to the second optical output surface 155 (i.e., the SLM 6 is arranged on the second optical output surface side of the device 15). The first light source 7, 71 is optically coupled to the first optical input surface 152, and the second light source 8, 81 is optically coupled to the second optical input surface 153. The telecentric lens configuration 11 is optically arranged between the SLM 6 and the second optical output surface 155. Substantially all principal rays strike the SLM 6 at a normal angle. The ray 100, which is the principal ray, strikes the SLM 6 at a normal angle (for the purpose of illustration, the ray 100 is shown slightly off the normal angle so as not to overlap itself in the illustration), and is reflected by the SLM 6 at a normal angle towards the pupil P, with its polarization rotated by the SLM 6. The ray 101, which is not the principal ray, is reflected by the SLM 6 differently (i.e., not at a normal angle) around the ray 100 and reaches the pupil P, after which its polarization is changed by the SLM 6. The purpose of this setup is to make the SLM image appear at infinity, which is a common goal of NED systems using waveguides.

[0031] In operation, light from the first light source 7, 71 enters through the first optical input surface 152 to be incident on the first polarization selective surface 13. Light of a first polarization (e.g., S or P polarization) is reflected through the second optical output surface 155 out of the optical device 15, transmitted through the telecentric lens configuration 11 so that the chief ray of the angular field impinges normally on the SLM 6, is reflected by the SLM 6 with a second polarization (e.g., P or S polarization), transmitted through the telecentric lens configuration 11 to enter the optical device 15 through the second optical output surface 155, transmitted through the second polarization selective surface 14, and output from the optical device 15 to the pupil P through the first optical output surface 154.

[0032] Figure 2A Only the illumination corresponding to the first light sources 7, 71 is shown, but the system 10 operates substantially symmetrically. That is, light from the second light sources 8, 81 enters through the second optical input surface 153 to be incident on the second polarization selective surface 14. Light of the first polarization (e.g., S or P polarization) is reflected through the second optical output surface 155 out of the optical device 15, transmitted through the telecentric lens configuration 11 so that the chief ray of the angular field impinges normally on the SLM 6, is reflected by the SLM 6 with the second polarization (e.g., P or S polarization), transmitted through the telecentric lens configuration 11 to enter the optical device 15 through the second optical output surface 155, transmitted through the first polarization selective surface 13, and output from the optical device 15 to the pupil P through the first optical output surface 154.

[0033] Figure 2DA system 10 is shown assembled to project light into a light-guide optical element (LOE) 50. Examples of LOE 50 are described in great detail, for example, in U.S. Pat. Nos. 7,643,214 and 7,724,442 to Amitai. LOE 50 includes a light-transmissive substrate 52 having a first major surface 52a and a second major surface 52b that are parallel to each other. LOE 50 also includes a surface 54 that is not parallel to the first major surface 52a and the second major surface 52b. Surface 54 couples light incident on surface 54 from system 10 into light-transmissive substrate 52. The width of surface 54 facing system 10, particularly toward the output end of device 15, corresponds to pupil P. Surface 54 may be reflective (e.g., mirror), refractive, or diffractive, and may thus reflect, refract, or diffract light so that the light is trapped between first major surface 52a and second major surface 52b by total internal reflection. LOE 50 may also include one or more light output elements (not shown), such as partially reflective surfaces that are non-parallel to first major surface 52a and second major surface 52b and couple light out of substrate 52. In one embodiment, instead of a LOE, element 50 may be a different polarization-sensitive near-eye display waveguide (e.g., a diffractive, reflective, holographic, or refractive waveguide).

[0034] FIG. 3A to FIG. 3D A novel system 10a is shown that is similar to system 10 of Figure 2, including a novel structure 15a that is similar to structure 15 of Figure 2 and additional components. System 10a uses prisms, mirrors, and waveguides to direct light from a light source to a novel optical device.

[0035] like Figure 3A As shown, the system 10a includes an SLM 6 disposed adjacent to the second optical output surface 155 (i.e., on the side of the second optical output surface 155), a first light source 7 optically coupled to the first optical input surface 152 through a prism 70, and a second light source 8 optically coupled to the second optical input surface 153 through a prism 80. The system 10a also includes mirrors 72, 82 that reflect light to waveguides 74, 84, which guide the light to the PBS surfaces 13, 14. The system 10a also includes a telecentric lens configuration 11 that is optically disposed between the SLM 6 and the second optical output surface 155.

[0036] In operation, light from the first light source 7 travels through the first prism 70 to be incident on the first mirror 72, is reflected to travel through the waveguide 74 to the first polarization selective surface 13. Light of a first polarization (e.g., S or P polarization) is reflected through the second optical output surface 155 out of the optical device 15a, is transmitted through the telecentric lens configuration 11 so that the chief ray of the angular field impinges normally on the SLM 6, is reflected by the SLM 6 with a second polarization (e.g., P or S polarization), is transmitted through the telecentric lens configuration 11 to enter the optical device 15a through the second optical output surface 155, is transmitted through the second polarization selective surface 14, and is output from the optical device 15a to the pupil P through the first optical output surface 154.

[0037] For the purpose of illustration, only the light corresponding to the LED 7 is shown in FIG3 . However, the system 10a operates substantially symmetrically. Light from the second light source 8 travels through the second prism 80 to be incident on the second mirror 82, is reflected to travel through the waveguide 84 to the second polarization selective surface 14. Light of the first polarization (e.g., S or P polarization) is reflected through the second optical output surface 155 to the outside of the optical device 15a, is transmitted through the telecentric lens configuration 11 so that the chief ray of the angular field is normally irradiated on the SLM 6, is reflected by the SLM 6 with the second polarization (e.g., P or S polarization), is transmitted through the telecentric lens configuration 11 to enter the optical device 15a through the second optical output surface 155, is transmitted through the first polarization selective surface 13, and is output from the optical device 15a to the pupil P through the first optical output surface 154.

[0038] Figure 3B A perspective view of system 10a is shown.

[0039] Figure 3C and Figure 3D An optical simulation is shown showing how light fills the system 10a, in particular the pupil P, for two fields. Figure 3C An optical simulation of filling the pupil P by the central field is shown. Figure 3D Optical simulations are shown for filling a pupil P by a non-central field. In each case, the chief ray strikes the SLM 6 at normal incidence.

[0040] Figure 4 and Figure 5 Shown with Figure 2A System 10 and Figure 3A Novel systems 10b and 10c are similar to system 10a, and novel systems 10b and 10c include novel structure 15b (similar to structures 15 and 15a) and novel structure 15, respectively. Compared with the previous embodiment in which the light source is usually (but not exclusively) polarized, in Figure 4 and Figure 5 In an embodiment, the light source 7 is not polarized.

[0041] exist Figure 4 In system 10b, light from light source 7 is directed to impinge on PBS 92 and is split between two polarizations (eg, S polarization and P polarization).

[0042] PBS 92 reflects light of a first polarization (e.g., S or P polarization) from light source 7, which travels through first waveguide 70 to be incident on first mirror 72, and is reflected to first polarization selective surface 13. Surface 13 reflects the first polarization light out of optical device 15b through second optical output surface 155 to be transmitted through telecentric lens configuration 11 so that the chief ray of the angular field impinges normally on SLM 6. SLM 6 reflects light with a second polarization (e.g., P or S polarization) to be transmitted through telecentric lens configuration 11 to enter optical device 15b through second optical output surface 155, to be transmitted through second polarization selective surface 14, and to be output from optical device 15b to pupil P through first optical output surface 154.

[0043] At the same time, the PBS 92 transmits the second polarized (e.g., P or S polarized) light from the light source 7, which travels through the optical path, including traveling through the third waveguide 90, being reflected by the third mirror 94, traveling through the second waveguide 80 to be incident on the second mirror 82, and being reflected to the second polarization selective surface 14. The polarization rotation device 96 is disposed somewhere along the optical path to rotate the polarization of the second polarized (e.g., P or S polarized) light to the first polarization (e.g., S or P polarization) along the optical path so that the second polarization selective surface 14 reflects the first polarized (e.g., S or P polarized) light through the second optical output surface 155 out of the optical device 15b to be transmitted through the telecentric lens configuration 11 so that the chief ray of the angular field impinges normally on the SLM 6. The SLM 6 reflects light with a second polarization (e.g., P or S polarization) to be transmitted through the telecentric lens configuration 11 to enter the optical device 15b through the second optical output surface 155, transmitted through the first polarization selective surface 13, and output from the optical device 15b to the pupil P through the first optical output surface 154.

[0044] exist Figure 5In the system 10c of FIG. 2 , unpolarized light from the light sources 7, 71 enters through the first optical input surface 152 to be incident on the first polarization selective surface 13. Light of a first polarization (e.g., S or P polarization) is reflected by the first polarization selective surface 13 to exit the optical device 15 through the second optical output surface 155, and the first polarization light is transmitted through the telecentric lens configuration 11 so that the chief ray of the angular field is normally impinged on the SLM 6. The SLM 6 reflects light with a second polarization (e.g., P or S polarization) to be transmitted through the telecentric lens configuration 11 to enter the optical device 15 through the second optical output surface 155, to be transmitted through the second polarization selective surface 14, and to be output from the optical device 15 to the pupil P through the first optical output surface 154. It can be appreciated from the above description that the processing of the first polarization light is the same as that of the system 10 of FIG. 2 , and therefore is not described in detail. Figure 5 Shown in.

[0045] However, the second polarization (e.g., P or S polarization) light from the light source 7 is transmitted by the first polarization selective surface 13 and the second polarization selective surface 14, exits through the second optical input surface 153, passes through the quarter wave plate 95 to rotate the polarization by a quarter wave, is reflected by the mirror 97, and passes through the quarter wave plate 95 again to rotate the polarization by an additional quarter wave to the first polarization (e.g., S or P polarization). The first polarization (e.g., S or P polarization) light enters the device 15 again through the second optical input surface 153 to be incident on the second polarization selective surface 14, which reflects the first polarization light through the second optical output surface 155 to exit the optical device 15 to be transmitted through the telecentric lens configuration 11 so that the chief ray of the angular field is normally impinged on the SLM 6. The SLM 6 reflects the light with the second polarization (e.g., P or S polarization) to be transmitted through the telecentric lens configuration 11 to enter the optical device 15 through the second optical output surface 155, transmit through the first polarization selective surface 13, and is output from the optical device 15 to the pupil P through the first optical output surface 154.

[0046] In the embodiment shown, a polarizer 99 may be introduced to prevent S-polarized light reflected directly upward by the polarization selective surfaces 13, 14 from reducing the system contrast.

[0047] definition

[0048] Included below are definitions of selected terms used herein. The definitions include various examples or forms of components that fall within the scope of the term and can be used in an implementation. The examples are not intended to be limiting. Both singular and plural forms of a term may be within a definition.

[0049] An "operable connection" or a connection through which entities are "operably connected" is a connection in which signals, physical communications, or logical communications can be sent or received. Typically, an operable connection includes a physical interface, an electrical interface, or a data interface, but it should be noted that an operable connection may include different combinations of these or other types of connections sufficient to allow operable control. For example, two entities may be operably connected by being able to transmit signals to each other directly or through one or more intermediate entities (such as a processor, operating system, logic, software, or other entity). Logical or physical communication channels may be used to create an operable connection.

[0050] To the extent that the terms "include" or "including" are employed in the detailed description or the claims, they are intended to be inclusive in a manner similar to the way the term "comprising" is interpreted when used as a transition word in a claim. Furthermore, to the extent that the term "or" is used in the detailed description or the claims (e.g., A or B), it is intended to mean "A or B or both." When applicants intend to indicate "only A or B but not both," then the term "only A or B but not both" will be employed. Thus, the use of the term "or" herein is inclusive, rather than exclusive. See Bryan A. Garner, A Dictionary of Modern Legal Usage 624 (2d ed. 1995) 624.

[0051] Although example systems, methods, etc. have been shown by describing examples, and although examples have been described in considerable detail, it is not the intention of the applicant to limit or in any way restrict the scope to such details. Of course, in order to describe the systems, methods, etc. described herein, it is impossible to describe every conceivable combination of components or methods. Additional advantages and modifications will be apparent to those skilled in the art. Therefore, the present invention is not limited to the specific details, representative devices, and illustrative examples shown and described. Therefore, the present application is intended to include changes, modifications, and variations that fall within the scope of the appended claims. In addition, the foregoing description is not meant to limit the scope of the present invention. Instead, the scope of the present invention is determined by the appended claims and their equivalents.

Claims

1. An optical device, include: a device body having a first optical input surface disposed at a first end of the device body and a second optical input surface disposed at a second end of the device body opposite to the first end, a first optical output surface disposed at a first side of the device body and a second optical output surface disposed at a second side of the device body opposite to the first side, an optical axis of the optical device being orthogonal to the first optical output surface and the second optical output surface; a first polarization selective surface configured to reflect incident light of a first polarization and transmit incident light of a second polarization orthogonal to the first polarization, the first polarization selective surface being disposed between the first optical input surface and the second optical input surface at a first angle α relative to the optical axis, such that light entering the optical device through the first optical input surface is incident on the first polarization selective surface, and the incident light of the first polarization is reflected through the second optical output surface to the outside of the optical device; as well as A second polarization selection surface, the second polarization selection surface is configured to reflect incident light of the first polarization and transmit incident light of the second polarization orthogonal to the first polarization, the second polarization selection surface is arranged between the first optical input surface and the second optical input surface at a second angle β relative to the optical axis, so that light entering the optical device through the second optical input surface is incident on the second polarization selection surface, and the incident light of the first polarization is reflected through the second optical output surface to the outside of the optical device, wherein β is approximately equal to -α.

2. An optical system, include: The optical device according to claim 1; a spatial light modulator (SLM) disposed adjacent to the second optical output surface; a first light source optically coupled to the first optical input surface, and a second light source optically coupled to the second optical input surface; a telecentric lens arrangement optically disposed between the SLM and the second optical output surface such that: light from the first light source enters through the first optical input surface to be incident on the first polarization selective surface, is reflected through the second optical output surface out of the optical device, is transmitted through the telecentric lens configuration so that the chief ray of the angular field impinges normally on the SLM, is reflected by the SLM with the second polarization, is transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, is transmitted through the second polarization selective surface, and is output from the optical device through the first optical output surface; and Light from the second light source enters through the second optical input surface to be incident on the second polarization selective surface, the first polarization light is reflected through the second optical output surface to the outside of the optical device, is transmitted through the telecentric lens configuration so that the main light of the angular field is normally impinged on the SLM, is reflected by the SLM with the second polarization, is transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, is transmitted through the first polarization selective surface, and is output from the optical device through the first optical output surface.

3. An optical system, include: The optical device according to claim 1; a spatial light modulator (SLM) disposed adjacent to said second optical output surface; a first prism and a second prism; a first mirror optically disposed between the first polarization selective surface and the first prism, and a second mirror optically disposed between the second polarization selective surface and the second prism; a first light source optically coupled to the first prism, and a second light source optically coupled to the second prism; a telecentric lens arrangement optically disposed between the SLM and the second optical output surface such that: light from the first light source travels through the first prism to be incident on the first mirror, is reflected onto the first polarization selective surface, is reflected out of the optical device through the second optical output surface with the first polarization, is transmitted through the telecentric lens configuration so that the chief ray of the angular field impinges normally on the SLM, is reflected by the SLM with the second polarization, is transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, is transmitted through the second polarization selective surface, and is output from the optical device through the first optical output surface; and Light from the second light source travels through the second prism to be incident on the second mirror, is reflected onto the second polarization selective surface, the first polarization light is reflected through the second optical output surface to the outside of the optical device, is transmitted through the telecentric lens configuration so that the chief ray of the angular field is normally incident on the SLM, is reflected by the SLM with the second polarization, is transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, is transmitted through the first polarization selective surface, and is output from the optical device through the first optical output surface.

4. An optical system, include: The optical device according to claim 1; a spatial light modulator (SLM) disposed on a second optical output surface side of the optical device; a first waveguide and a second waveguide; a first mirror optically disposed between the first polarization selective surface and the first waveguide, and a second mirror optically disposed between the second polarization selective surface and the second waveguide; a third mirror and a third waveguide optically coupled to the second waveguide; a polarization beam splitter (PBS) optically coupled to the first waveguide and the third waveguide; a polarization rotation device optically coupled to the third waveguide; a light source optically coupled to the PBS; a telecentric lens arrangement optically disposed between the SLM and the second optical output surface such that: a first polarization of light from the light source is reflected by the PBS, travels through the first waveguide to be incident on the first mirror, is reflected onto the first polarization selective surface, is reflected out of the optical device through the second optical output surface, is transmitted through the telecentric lens configuration such that a chief ray of an angular field impinges normally on the SLM, is reflected by the SLM with the second polarization, is transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, is transmitted through the second polarization selective surface, and is output from the optical device through the first optical output surface; and A second polarized light from the light source is transmitted by the PBS to travel through an optical path, including traveling through the third waveguide, being reflected by the third mirror, traveling through the second waveguide to be incident on the second mirror, being reflected onto the second polarization selective surface, the polarization rotation device rotating the polarization of the second polarized light to the first polarization along the optical path, so that the first polarized light is reflected through the second optical output surface out of the optical device, transmitted through the telecentric lens configuration so that the chief ray of the angular field is normally incident on the SLM, reflected by the SLM with the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the first polarization selective surface, and output from the optical device through the first optical output surface.

5. An optical system, include: The optical device according to claim 1; a spatial light modulator (SLM) disposed on a second optical output surface side of the optical device; a light source optically coupled to the first optical input surface; a mirror disposed adjacent to said second optical input surface; a quarter wave plate optically coupled between the mirror and the second optical input surface; a telecentric lens arrangement optically disposed between the SLM and the second optical output surface such that: light from the light source enters through the first optical input surface to be incident on the first polarization selective surface, wherein light of a first polarization from the light source is reflected from the first polarization-selective surface out of the optical device through the second optical output surface, is transmitted through the telecentric lens configuration such that the chief ray of the angular field impinges normally on the SLM, is reflected by the SLM with the second polarization, is transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, is transmitted through the second polarization-selective surface, and is output from the optical device through the first optical output surface; and wherein a second polarized light from the light source is transmitted by the first polarization selective surface and the second polarization selective surface, exits through the second optical input surface, passes through the quarter wave plate to rotate the polarization by a quarter wave, is reflected by the mirror, passes through the quarter wave plate again to rotate the polarization by an additional quarter wave to the first polarization, enters again through the second optical input surface to be incident on the second polarization selective surface, the first polarized light is reflected out of the optical device through the second optical output surface, is transmitted through the telecentric lens configuration so that the main ray of the angular field is irradiated normally on the SLM, is reflected by the SLM with the second polarization, is transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, is transmitted through the first polarization selective surface, and is output from the optical device through the first optical output surface.

6. The optical device according to claim 1, in, The first angle α is in the range of 30° to 75° relative to the optical axis, or wherein the first angle α is one of 45° or 60° relative to the optical axis.

7. A system comprising the optical device according to claim 1, in, The system includes a light guide optical element (LOE) or other polarization-sensitive near-eye display waveguide into which light from the optical device is projected.

8. An optical device, include: a device body formed by adjoining at least three optical sections, each of the at least three optical sections being made of an optically transparent material, the device body having a first optical input surface disposed at a first end of the device body and a second optical input surface disposed at a second end of the device body opposite to the first end, a first optical output surface disposed at a first side of the device body and a second optical output surface disposed at a second side of the device body opposite to the first side, an optical axis of the optical device being orthogonal to the first optical output surface and the second optical output surface; one or more polarization selective coatings or foils disposed between the at least three portions, wherein the one or more polarization selective coatings or foils are configured to reflect incident light of a first polarization and transmit incident light of a second polarization orthogonal to the first polarization, such that adjoining surfaces of the at least three optical portions form a first polarization selective surface and a second polarization selective surface; the first polarization selective surface disposed between the first optical input surface and the second optical input surface at a first angle α relative to the optical axis such that the first polarization selective surface reflects incident light of the first polarization out of the optical device through the second optical output surface; and The second polarization selective surface is arranged between the first optical input surface and the second optical input surface at a second angle β relative to the optical axis, so that the second polarization selective surface reflects the incident light of the first polarization to pass through the second optical output surface to leave the optical device, wherein β is approximately equal to -α.

9. An optical system, include: The optical device according to claim 8; a spatial light modulator (SLM) disposed adjacent to the second optical output surface; a first light source optically coupled to the first optical input surface, and a second light source optically coupled to the second optical input surface; a telecentric lens arrangement optically disposed between the SLM and the second optical output surface such that: light from the first light source enters through the first optical input surface to be incident on the first polarization selective surface, reflects out of the optical device through the second optical output surface with the first polarization, is transmitted through the telecentric lens configuration so that the chief ray of the angular field impinges normally on the SLM, is reflected by the SLM with the second polarization, is transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, is transmitted through the second polarization selective surface, and is output from the optical device through the first optical output surface; and Light from the second light source enters through the second optical input surface to be incident on the second polarization selective surface, reflects out of the optical device through the second optical output surface with the first polarization, is transmitted through the telecentric lens configuration so that the chief ray of the angular field impinges normally on the SLM, is reflected by the SLM with the second polarization, is transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, is transmitted through the first polarization selective surface, and is output from the optical device through the first optical output surface.

10. An optical system, include: The optical device according to claim 8; a spatial light modulator (SLM) disposed adjacent to the second optical output surface; a first prism and a second prism; a first mirror optically disposed between the first polarization selective surface and the first prism, and a second mirror optically disposed between the second polarization selective surface and the second prism; a first light source optically coupled to the first prism, and a second light source optically coupled to the second prism; a telecentric lens arrangement optically disposed between the SLM and the second optical output surface such that: light from the first light source travels through the first prism to be incident on the first mirror, is reflected onto the first polarization selective surface, reflects out of the optical device with the first polarization through the second optical output surface, is transmitted through the telecentric lens configuration so that the chief ray of the angular field impinges normally on the SLM, is reflected by the SLM with the second polarization, is transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, is transmitted through the second polarization selective surface, and is output from the optical device through the first optical output surface; and Light from the second light source travels through the second prism to be incident on the second mirror, is reflected onto the second polarization selective surface, reflects out of the optical device through the second optical output surface with the first polarization, is transmitted through the telecentric lens configuration so that the chief ray of the angular field impinges normally on the SLM, is reflected by the SLM with the second polarization, is transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, is transmitted through the first polarization selective surface, and is output from the optical device through the first optical output surface.

11. An optical system, include: The optical device according to claim 8; a spatial light modulator (SLM) disposed on a second optical output surface side of the optical device; a first waveguide and a second waveguide; a first mirror optically disposed between the first polarization selective surface and the first waveguide, and a second mirror optically disposed between the second polarization selective surface and the second waveguide; a third mirror and a third waveguide optically coupled to the second waveguide; a polarization beam splitter (PBS) optically coupled to the first waveguide and the third waveguide; a polarization rotation device optically coupled to the third waveguide; a light source optically coupled to the PBS; a telecentric lens arrangement optically disposed between the SLM and the second optical output surface such that: light of a first polarization from the light source is reflected by the PBS, travels through the first waveguide to be incident on the first mirror, is reflected onto the first polarization selective surface, reflects out of the optical device through the second optical output surface, is transmitted through the telecentric lens configuration such that the chief ray of the angular field impinges normally on the SLM, is reflected by the SLM with the second polarization, is transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, is transmitted through the second polarization selective surface, and is output from the optical device through the first optical output surface; and A second polarized light from the light source is transmitted by the PBS to travel through an optical path, including traveling through the third waveguide, being reflected by the third mirror, traveling through the second waveguide to be incident on the second mirror, being reflected onto the second polarization selective surface, the polarization rotation device rotating the polarization of the second polarized light to the first polarization along the optical path, so that the first polarized light is reflected out of the optical device through the second optical output surface, transmitted through the telecentric lens configuration so that the chief ray of the angular field is normally incident on the SLM, reflected by the SLM with the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the first polarization selective surface, and output from the optical device through the first optical output surface.

12. An optical system, include: The optical device according to claim 8; a spatial light modulator (SLM) disposed on a second optical output surface side of the optical device; a light source optically coupled to the first optical input surface; a mirror disposed adjacent to said second optical input surface; a quarter wave plate optically coupled between the mirror and the second optical input surface; a telecentric lens arrangement optically disposed between the SLM and the second optical output surface such that: light from the light source enters through the first optical input surface to be incident on the first polarization selective surface, wherein light of a first polarization from the light source is reflected from the first polarization-selective surface out of the optical device through the second optical output surface, is transmitted through the telecentric lens configuration such that the chief ray of the angular field impinges normally on the SLM, is reflected by the SLM with the second polarization, is transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, is transmitted through the second polarization-selective surface, and is output from the optical device through the first optical output surface; and wherein a second polarized light from the light source is transmitted by the first polarization selective surface and the second polarization selective surface, exits through the second optical input surface, passes through the quarter wave plate to rotate the polarization by a quarter wave, is reflected by the mirror, passes through the quarter wave plate again to rotate the polarization by an additional quarter wave to the first polarization, enters again through the second optical input surface to be incident on the second polarization selective surface, the first polarized light is reflected out of the optical device through the second optical output surface, is transmitted through the telecentric lens configuration so that the main ray of the angular field is irradiated normally on the SLM, is reflected by the SLM with the second polarization, is transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, is transmitted through the first polarization selective surface, and is output from the optical device through the first optical output surface.

13. The optical device according to claim 8, in, The first angle α is in the range of 30° to 75° relative to the optical axis.

14. The optical device according to claim 8, in, The first angle α is one of 45° and 60° relative to the optical axis.

15. A method for an optical device, include: emitting light from one or more light sources; directing the emitted light toward a first beam splitter surface and a second beam splitter surface of the optical device; reflecting a first polarized light by the first beam splitter surface and the second beam splitter surface so that the first polarized light impinges on a spatial light modulator (SLM) at normal incidence; as well as The first polarized light is modulated using the SLM to form an image.

16. The method according to claim 15, include: reflecting image light by the SLM at a second polarization orthogonal to the first polarization; as well as The second polarized light is transmitted through the first beam splitter surface and the second beam splitter surface to be coupled out of the optical device.

17. The method according to claim 16, in, Directing the emitted light toward a first beam splitter surface and a second beam splitter surface of the optical device comprises: directing light from a first light source of the one or more light sources through a first waveguide; Reflecting the light from the first light source onto the surface of the first beam splitter; directing light from a second light source of the one or more light sources through a second waveguide; and The second light source light is reflected onto the second beam splitter surface.

18. The method according to claim 16, in, Directing the emitted light toward a first beam splitter surface and a second beam splitter surface of the optical device comprises: Splitting the emitted light into first polarized light and second polarized light by a third beam splitter surface; reflecting the first polarized light by the surface of the third beam splitter; directing the first polarized light to be incident on a first mirror; reflecting the first polarized light toward the first beam splitter surface; transmitting the second polarized light through the third beam splitter surface; directing the second polarized light to be incident on a second mirror; rotating the polarization of the second polarized light to the first polarization; and The first polarized light is reflected toward the second beam splitter surface.

19. The method according to claim 16, in, Directing the emitted light toward a first beam splitter surface and a second beam splitter surface of the optical device comprises: Splitting the emitted light into first polarized light and second polarized light by a third beam splitter surface; reflecting the first polarized light by the surface of the third beam splitter; directing the first polarized light to be incident on a first mirror; reflecting the first polarized light toward the first beam splitter surface; transmitting the second polarized light through the third beam splitter surface; rotating the polarization of the second polarized light to the first polarization; directing the first polarized light to be incident on a second mirror; and The first polarized light is reflected toward the second beam splitter surface.

20. The method according to claim 16, in, The reflecting the first polarized light by the first beam splitter surface and the second beam splitter surface so that the first polarized light is incident on the SLM at normal incidence comprises: transmitting the second polarized light through the first beam splitter surface and the second beam splitter surface; passing the second polarized light through a quarter wave plate to rotate the polarization by a quarter wave; Reflects light that has been rotated by a quarter wave; passing the quarter-wave rotated light again through the quarter-wave plate to rotate the polarization an additional quarter wave to the first polarization; and The first polarized light is reflected by the second beam splitter surface toward the SLM.

Images