Optical element (OE) for combining the outputs of multiple light emitters into a globally weighted intensity output

Abstract

To provide an optical element.SOLUTION: An optical element (OE) includes a body formed such that the body generates an output electromagnetic field at an output surface disposed at a second surface of the body in response to an array of light emitters emitting at least partially overlapping input electromagnetic fields toward the body to form a combined input electromagnetic field at a first surface of the body. An intensity of the output electromagnetic field at the output surface remains unchanged or substantially unchanged between a first time when all of the light emitters are emitting the electromagnetic field and a second time when one or more subsets of the light emitters are not emitting the electromagnetic field. The intensity of the output electromagnetic field remains substantially unchanged when one or more portions or areas of the output electromagnetic field continue to be irradiated at a reduced intensity at a second time relative to the first time.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 677,100, filed July 30, 2024, the entire contents of which are incorporated herein by reference.

[0002] 1) Field

[0003] The present disclosure relates to diffractive beam splitters and shapers designed to operate with multi-emitter / aperture (array) light sources. [Background technology]

[0004] 2) Background In lighting technologies in the mobile communications, AR / VR, consumer electronics, and LIDAR markets, there is a strong demand for combining the output of multiple light sources into a combined output pattern for applications such as 3D sensing, as increasing output power can improve sensing distance, field of view, and accuracy. Many prior art devices (e.g., Apple's Face ID structured light generator) create a global output light pattern through "tiling," which involves repeatedly stitching smaller subsection outputs ("tiles") vertically and horizontally. Each "tile" corresponds to the processed output (e.g., split) of a single light emitter or light source, such as one vertical-cavity surface-emitting laser (VCSEL) in a VCSEL array. The output tiles of the single light source are deflected by a lens and aligned into the global output pattern. This approach requires multiple optical surfaces to split / shape the individual emitter outputs and subsequently deflect / "til" them to obtain a combined output. The spatially repetitive (quasi-periodic) nature of the "tiling" approach does not allow for the creation of globally optimized output functions, such as intensity profiles weighted according to powers of an arccosine function, or for output angle specific beam shaping in the case of dot or spot generation. As a result, prior art approaches to creating a global output light pattern by "tiling" result in areas or portions of the output light density distribution in the global output light pattern when one of the light emitters or light sources is turned off, i.e., the area or portion is devoid of light. Summary of the Invention [Problem to be solved by the invention]

[0005] [Means for solving the problem]

[0006] This disclosure describes an optical element (OE) with beam shaper properties, specifically a diffractive OE, and its design method for combining multiple light sources into a single global output pattern. This approach achieves a globally optimized output of intensity and phase, e.g., divergence, using a single integrated beam shaper. The OE output fields are substantially overlapping or identical at all emitters. In this specification, terms such as "optical element," "OE," "beam shaper," and "diffractive beam shaper" may be used interchangeably.

[0007] The present disclosure discloses an exemplary OE that provides a single, globally optimized design output pattern from an array of light sources, particularly an array of edge-emitting lasers, that includes the following features:

[0008] Collimation of each output beam.

[0009] Division into a rectangular grid of spots characterized by regular angular spacing.

[0010] Control of the beam profile at the output plane (e.g., correcting anamorphic distortions of the spot shape).

[0011] Pincushion / barrel distortion control.

[0012] and global angular intensity profile control.

[0013] The disclosed exemplary OEs are furthermore relatively insensitive to lateral misalignment and can function at a distance from an array of edge-emitting lasers where the individual laser emitter outputs overlap. As used herein, terms such as "laser," "optical emitter," and "light source" may be used interchangeably, and terms such as "electromagnetic field," "light," and "laser light" may be used interchangeably.

[0014] More particularly, disclosed is an optical element (OE) for combining the outputs of N optical emitters into an output with a globally weighted intensity or intensity distribution. The OE includes a body configured to generate an output electromagnetic field at an output surface disposed on a second surface of the body in response to the N optical emitters emitting N at least partially overlapping electromagnetic fields toward the body to form an input electromagnetic field at a first surface of the body. The body is configured to manipulate or shape the input electromagnetic field as it passes through the body such that the intensity or intensity distribution at the output surface of the output electromagnetic field remains unchanged or substantially unchanged between a first time when the N optical emitters are emitting the N electromagnetic fields and a second time when M of the N optical emitters are emitting the M electromagnetic fields. <N、N≧3、かつM≧2である。

[0015] In an example that may include the intensity or intensity distribution of the output electromagnetic field remaining substantially unchanged, the intensity or intensity distribution at the output face of the output electromagnetic field remains substantially unchanged when one or more portions or areas of the output electromagnetic field at the output face each have a reduced intensity at a second time relative to a first time but do not extinguish, with the remaining portions or areas of the output electromagnetic field having the same intensity or intensity distribution at the first time and the second time. In a non-limiting example, the term "not extinguished," when used in connection with one or more portions or areas of the output electromagnetic field having reduced intensity at the output face, means that each of the one or more portions of the output electromagnetic field has a Y amount of radiance greater than zero impinging on the portion at the second time relative to an X amount of radiance impinging on the portion at the first time, where X > Y. As used herein, "radiance" may be defined as the radiant flux emitted, reflected, transmitted, or received by a surface per unit solid angle per unit projected area.

[0016] Also disclosed is an optical system including an optical element (OE) having a first surface and a second surface. An array of light emitters is disposed and is operable to emit at least partially overlapping input electromagnetic fields into the first surface of the OE to form a combined input electromagnetic field at the first surface of the OE. In response to the combined input electromagnetic fields, the OE generates an output electromagnetic field at an output surface disposed on the second surface of the OE. The intensity or intensity distribution of the output electromagnetic field at the output surface remains unchanged or substantially unchanged between a first time when all of the light emitters in the array of light emitters are emitting the input electromagnetic field and a second time when one or more subsets of the light emitters in the array of light emitters are not emitting the input electromagnetic field.

[0017] In an example that may include the intensity or intensity distribution of the output electromagnetic field remaining substantially unchanged, the intensity or intensity distribution of the output electromagnetic field remains substantially unchanged when one or more portions or areas of the output electromagnetic field each remain illuminated at a reduced intensity at a second time relative to a first time, but are not extinguished. In this example, the remaining portions or areas of the output electromagnetic field may have the same intensity at the first time and the second time.

[0018] In another example of what may constitute the output electromagnetic field remaining substantially unchanged in intensity or intensity distribution, the intensity or intensity distribution of the output electromagnetic field remains substantially unchanged when N-M number of the light emitters stop emitting light, and the change in intensity in one or more portions or areas of the output electromagnetic field is approximately (N-M) / N%, where N = the total number of light emitters in the array of light emitters, and M = the number of light emitters in the array of light emitters that emit the output electromagnetic field after N-M number of the light emitters stop emitting the output electromagnetic field. For example, when N = 100 and M = 98, the change in intensity or intensity distribution is (100-98) / 100% to 2%.

[0019] In another example, the intensity or intensity distribution at the output plane of the output electromagnetic field may remain substantially unchanged (may be averaged) over a time scale that may be a multiple of 3, 10, 20, 100, etc. coherence times. On time scales that are short compared to the coherence time, variations in the intensity or intensity distribution of the output electromagnetic field may occur due to speckle. [Brief explanation of the drawings]

[0020] [Figure 1A]FIG. 1 is a schematic side view of an example optical system including an example array of light sources (light emitters) each emitting or projecting an input electromagnetic field or input electromagnetic radiation, e.g., laser light, onto an optical element according to the present principles, the optical element configured to manipulate or shape the input electromagnetic field as it passes through the body to form an output electromagnetic field whose intensity or intensity distribution at an output face remains unchanged or substantially unchanged between a first time when N light emitters are emitting N electromagnetic fields and a second time when fewer than N light emitters are emitting the electromagnetic field.

[0021] [Figure 1B] 1B is a plan view of an exemplary 1×X array of the exemplary array of light sources of FIG. 1A, where X≧2, taken along line IB-IB of FIG. 1A.

[0022] [Figure 1C] 1B is a plan view of an example X×Y array of the example array of light sources of FIG. 1A taken along line IC-IC of FIG. 1A, where X≧2 and Y≧2.

[0023] [Figure 2] FIG. 1B is a perspective view of the exemplary optical element of FIG. 1A, including an array of spaced apart cylindrical protrusions or posts of different diameters but a common height extending from a base of the exemplary optical element in the +Z direction.

[0024] [Figure 3] FIG. 1B is a perspective view of another exemplary optical element of FIG. 1A, including an array of spaced apart cylindrical protrusions or posts of varying diameters and heights extending from a base of the exemplary optical element in the +Z direction.

[0025] [Figure 4] 1B is a plan view of the circular surface of the top of the cylindrical protrusion shown in FIG. 2 and / or FIG. 3 facing the output surface shown in FIG. 1A.

[0026] [Figure 5]1B is a perspective view of yet another example optical element of FIG. 1A including an array of rectangular parallelepiped-shaped protrusions or posts of varying heights extending in the +Z direction from a base of the example optical element.

[0027] [Figure 6A] 1B is a perspective view of a portion of another example optical element of FIG. 1A including a continuously varying, undulating, or wavy surface thickness. [Figure 6B] 1B is a perspective view of a portion of another example optical element of FIG. 1A including a continuously varying, undulating, or wavy surface thickness.

[0028] [Figure 7] 1B is a perspective view of yet another example optical element of FIG. 1A including different refractive indices.

[0029] [Figure 8A] 1A and 1B are example target and actual intensity profiles generated on the output surface of FIG. 1A by the example amplitude and phase plots of FIG. 10A and FIG. 10B projected by an array of example light sources of FIG. 1A onto the side or face of the example optical element of FIG. 1A closest to the light sources of FIG. 1A. [Figure 8B] 1A and 1B are example target and actual intensity profiles generated on the output surface of FIG. 1A by the example amplitude and phase plots of FIG. 10A and FIG. 10B projected by an array of example light sources of FIG. 1A onto the side or face of the example optical element of FIG. 1A closest to the light sources of FIG. 1A.

[0030] [Figure 9A] 8B is an example cross-sectional view of an example target intensity profile taken along line IXA-IXA of FIG. 8A.

[0031] [Figure 9B] 8C is an example cross-sectional view of an example actual intensity profile taken along line IXB-IXB of FIG. 8B.

[0032] [Figure 10A] 1A is an example amplitude and phase plot of electromagnetic radiation emitted or projected by the example array of light sources of FIG. 1A onto the side or face of the example optical element of FIG. 1A nearest the example array of light sources of FIG. 1A, which in one example consists of a 1×20 array of light sources. [Figure 10B] 1A is an example amplitude and phase plot of electromagnetic radiation emitted or projected by the example array of light sources of FIG. 1A onto the side or face of the example optical element of FIG. 1A nearest the example array of light sources of FIG. 1A, which in one example consists of a 1×20 array of light sources. DETAILED DESCRIPTION OF THE INVENTION

[0033] Various non-limiting embodiments will now be described with reference to the accompanying drawings, in which like reference numbers correspond to similar or functionally equivalent elements or features.

[0034] As used herein, spatial or directional terms such as "left," "right," "inner," "outer," "above," "below," "top," "bottom," and the like, refer to the present disclosure as shown in the drawing figures. However, it is understood that the present disclosure can assume various alternative orientations, and therefore, such terms should not be considered limiting. Furthermore, as used herein, all numbers expressing dimensions, physical properties, processing parameters, quantities of ingredients, reaction conditions, and the like, used in the specification and claims, should be understood to be modified in all instances by the term "approximately" or "about." Thus, unless otherwise indicated, the numerical values ​​set forth in the following specification and claims may vary depending on the desired properties sought to be obtained by the present disclosure.

[0035] At the very least, each numerical value should be construed in light of at least the number of reported significant digits and by applying ordinary rounding techniques; however, this is not intended to limit the application of the doctrine of equivalents to the scope of the claims. Moreover, all ranges disclosed herein should be understood to encompass the beginning and ending values ​​of the range, as well as any and all subranges subsumed therein. For example, a range of "1 to 10" should be deemed to include any and all subranges between the minimum value of 1 and the maximum value of 10 (inclusive), i.e., all subranges beginning with a minimum value of 1 or greater and ending with a maximum value of 10 or less, e.g., 1 to 3.3, 4.7 to 7.5, 5.5 to 10, etc. "A" or "an" refers to one or more.

[0036] As used herein, the terms "coupled," "couple," and similar terms refer to two or more elements that are joined, coupled, secured, connected, placed in communication, or otherwise associated (e.g., mechanically, electromagnetically, fluidly, optically) with one another. In various examples, the elements can be associated directly or indirectly. As an example, element A can be directly associated with element B. As another example, element A can be indirectly associated with element B, e.g., through another element C. It will be understood that not all associations between the various disclosed elements are necessarily depicted. Thus, other couplings than those depicted in the figures may exist.

[0037] As used herein, the phrase "at least one of," when used in conjunction with a list of items, means that various combinations of one or more of the listed items can be used, and that only one of each item in the list may be required. For example, "at least one of item A, item B, and item C" can include, but is not limited to, item A, or item A and item B. This example can also include item A, item B, and item C, or item B and item C. In other examples, "at least one of" can be, for example, but is not limited to, two items A, one item B, and ten items C; four items B and seven items C; and other suitable combinations.

[0038] 1A-1C, an optical system according to the principles of the present disclosure includes an optical element (OE) 2, e.g., a diffractive OE, having a first surface 4 and a second surface 6. Disposed at a distance d1, e.g., 0.56 millimeters, from the first surface 4 of the OE2 is an array 8 of light emitters 10 operable to emit multiple individual input electromagnetic fields 12 (as indicated by reference numeral 40) that at least partially overlap one another to form a combined input electromagnetic field 14 at the first surface 4 of the OE2.

[0039] As shown in Figure 1B, the array 8 of light emitters 10 may be a 1 x X array of light emitters 10, where X > 2. Alternatively, as shown in Figure 1C, the array 8 of light emitters 10 may be an X x Y array of light emitters 10, where X > 2, Y > 2, and X and Y may be the same or different. By way of example, the array 8 of light emitters 10 may be a 1 x 20 array of single mode light emitters 10 distributed horizontally with a center-to-center spacing of 22 μm.

[0040] As a non-limiting example, each optical emitter 10 of array 8 may be a semiconductor laser having the following performance characteristics: a center wavelength of 1380 nm, a spectral bandwidth of 6 nm, a coherence length of 101 μm (coherence time=337 fs), and horizontal and vertical half-power divergence angles of 11.8 degrees and 19.9 degrees. However, this should not be construed in a limiting sense, as it is envisioned that each optical emitter 10 of array 8 may have one or more different performance characteristics.

[0041] OE2 is configured such that, in response to the combined input electromagnetic field 14, OE2 produces an output electromagnetic field 18 at an output face 16 disposed at a distance d2, eg, 5 meters, from a second face 6 of OE2.

[0042] In accordance with the principles of the present disclosure, OE2 is configured such that, in response to the composite input electromagnetic field 14, the intensity or intensity distribution of the output electromagnetic field 18 at the output face 16 remains unchanged or substantially unchanged between a first time when all of the light emitters 10 of the array of light emitters 8 are emitting their individual electromagnetic fields 12, and a second time when one or more subsets of the light emitters 10 of the array of light emitters 8 are not emitting their individual electromagnetic fields 12.

[0043] In one example, the intensity or intensity distribution at output face 16 of the output electromagnetic field remains substantially unchanged when one or more portions or areas of output electromagnetic field 18 at output face 16 each have a reduced intensity, but do not disappear, at a first time when all of the light emitters 10 of array 8 of light emitters are emitting their individual electromagnetic fields 12, relative to a second time when one or more subsets of light emitters 10 of array 8 of light emitters are not emitting their individual electromagnetic fields 12. In this example, the remaining portions or areas of the output electromagnetic field have the same intensity at both the first time and the second time.

[0044] In another example of what may constitute the output electromagnetic field remaining substantially unchanged in intensity or intensity distribution, the intensity or intensity distribution of the output electromagnetic field remains substantially unchanged when N-M number of the light emitters stop emitting light, and the change in intensity or intensity distribution in one or more portions or areas of the output electromagnetic field is about (N-M) / N%. For example, when N=100 and M=98, the change in intensity or intensity distribution is (100-98) / 100-2%.

[0045] In summary, depending on the number of light emitters 10 that may not be emitting their individual electromagnetic fields 12 at the second time, the local intensity, intensity distribution, or brightness of output electromagnetic field 18 at one or more locations on output face 16 may be different, but not eliminated, at the second time compared to when all of the light emitters 10 were emitting their individual electromagnetic fields 12 at the first time. In other words, those one or more locations on output face 16 continue to be illuminated at the second time, albeit with a reduced intensity, relative to the illumination of the same one or more locations on output face 16 at the first time.

[0046] 1A , and in particular, the operation of an OE2 configured to manipulate or shape a composite input electromagnetic field 14 as it passes through the body of the OE2 such that the intensity or intensity distribution at the output face of the output electromagnetic field 18 remains unchanged or substantially unchanged when up to 10%, 20%, or 30% of the light emitters 10 in the array 8 of light emitters are not outputting their individual electromagnetic fields 12, relative to when all of the light emitters 10 in the array 8 of light emitters are outputting their individual electromagnetic fields 12. Now, having described the operation of the optical system of FIG. 1A , and in particular an OE2 configured to manipulate or shape a composite input electromagnetic field 14 as it passes through the body of the OE2 such that the intensity or intensity distribution at the output face of the output electromagnetic field 18 remains unchanged or substantially unchanged when up to 10%, 20%, or 30% of the light emitters 10 in the array 8 of light emitters are not outputting their individual electromagnetic fields 12, relative to when all of the light emitters 10 in the array 8 of light emitters are outputting their individual electromagnetic fields 12, a different non-limiting example of an OE2 will now be described with reference to FIGS. 2-7 , in which the OE2 is configured from a single, integrated body that may be formed in a manner well known in the art of semiconductor processing. Furthermore, each OE2 may be formed from any suitable and / or desirable optical material that enables the OE to operate in the manner disclosed herein. Non-limiting examples of such optical materials can include glass or crystalline dielectric materials (e.g., SiO, borosilicate glass, AlO, CaF, or MgF), semiconductor materials (e.g., Ge, Si, GaAs, or InP), or polymers (e.g., polymethyl methacrylate (PMMA) or polycarbonate). However, this list of optical materials should not be construed in a limiting sense, as it is contemplated that the OE2 can be formed of any suitable and / or desirable optical material, now known or later developed, that enables the OE to operate in the manner disclosed in this disclosure.

[0047] 2, and with continuing reference to all preceding figures, an example OE2 may include a single, integrated body 24 that may include a first face 4 that includes a base 25 that may include a flat surface 26. In one example, the OE2 may be oriented to receive a combined input electromagnetic field 14 that is launched into the first face 4 of the OE2 by an array 8 of light emitters.

[0048] The second face 6 of the body 24 may include an array of protrusions or posts 28, each of which may include a longitudinal axis 30 that may extend away from, for example perpendicular to, the planar surface 26. In one example, the combined input electromagnetic field 14 passes through the OE2 and is modified or shaped into an output electromagnetic field 18 at the output face 16 by the diffractive properties of the OE2.

[0049] In this example, each protrusion or post 28 may have a cylindrical shape, a circular cross-section, and a flat surface opposite flat surface 26. The array of protrusions or posts 28 may include protrusions or posts 28 that may be spaced apart from one another and may have protrusions or posts 28 with different diameters. In OE2 of FIG. 2, all of the protrusions or posts may have the same height h from flat surface 26.

[0050] With reference to FIG. 3, and with continuing reference to all preceding figures, the OE2 shown in FIG. 3 is similar to the OE2 shown in FIG. 2, with the following exception: in FIG. 3, the array of protrusions or posts 28 may include protrusions or posts 28 that may have any number of different heights, e.g., heights h1 and h2, from the flat surface 26.

[0051] FIG. 4 is a plan view of the second surface 6 of the OE 2 shown in FIG. 2 or FIG.

[0052] With reference to FIG. 5 and with continuing reference to all preceding figures, another example OE2 may include a single, integrated body 24 that may include a base 25 on a first side 4 of the body 24 that includes a flat surface 26 for receiving input electromagnetic fields 12 that are combined to form a combined input electromagnetic field 14 that is input to the OE2.

[0053] The second face 6 of the body 24 may include an array of protrusions or posts 28, each of which may include a longitudinal axis 30 that may extend away from, for example perpendicular to, the planar surface 26. In one example, the combined input electromagnetic field 14 passes through the OE2 of FIG. 5 and is modified or shaped into an output electromagnetic field 18 at the output face 16 by the diffractive properties of the OE2.

[0054] In this example, each protrusion or post 28 may have an elongated cube or rectangular shape, a square or rectangular cross-section, and a flat surface opposite the flat surface 26. Each elongated cube-shaped protrusion or post 28 may extend from a base 25 that includes a flat surface 26 on one side of the base and an array of protrusions or posts 28 on the other side of the base 25. In the example of OE2 shown in FIG. 5, the dashed lines indicating the extent of the elongated cube-shaped protrusions or posts 28 and base 25 are shown for reference purposes only to aid in the explanation and understanding of the OE2 shown in FIG. 5. For this purpose, it should be appreciated that the OE2 shown in FIG. 5, like the OE2 shown in FIGS. 2 and 3, is formed from a single, unitary body 24 that is etched to form the protrusions or posts 28 on the second side 6 of the OE2. Finally, the array of protrusions or posts 28 of OE2 shown in FIG. 5 may include protrusions or posts 28 that may vary in height above the flat surface 26.

[0055] The spacing or absence of spacing between adjacent protrusions or columns 28 and / or the same or different heights of the protrusions or columns 28 in the various examples of OE2 shown in Figures 2-5 can encode the phase change of the output electromagnetic field 18 at the output face 16.

[0056] By way of example, it is contemplated that the various features of OE2 shown in Figures 2-5 may be combined, mixed, and / or adapted in any manner deemed appropriate and / or desirable by one of ordinary skill in the art for a particular application. For example, each of the elongated cubic projections or posts 28 in Figure 5 may extend from the base 25 in a spaced-apart relationship, similar to the cylindrical projections or posts 28 shown in Figures 2 and 3 that extend from the base 25 in a spaced-apart relationship.

[0057] In another example, the array of protrusions or columns 28 of OE2 shown in FIG. 5 may include protrusions or columns 28 that may have the same height above the flat surface 26 as the protrusions or columns 28 shown in FIG. 2.

[0058] In another example, the array of protrusions or columns 28 of OE2 shown in Figures 2-5 may include one or more areas or regions that include protrusions or columns 28 of the same height and one or more other areas or regions that include protrusions or columns 28 of different heights.

[0059] In another example, the shapes of the protrusions or posts 28 may be different. For example, a subset of the protrusions or posts 28 may have a first shape, such as, but not limited to, a cylindrical shape with a circular cross section, while another subset of the protrusions or posts 28 may have a second shape, such as, but not limited to, a cubic shape projected onto a square or rectangle.

[0060] Furthermore, the shapes and / or cross-sections of the protrusions or posts 28 described herein should not be construed as limiting, as it is contemplated that one, some, or all of the protrusions or posts 28 may have any shape and / or cross-section that is deemed appropriate and / or desirable for a particular application, including protrusions or posts 28 having different shapes and / or cross-sections.

[0061] Accordingly, disclosure herein of various features of the OE2 shown in Figures 2-5 should not be construed in a limiting sense.

[0062] 6A and 6B, another example OE2 may include a single, integrated body 24 that may include a base 25 at a first face 4 of the body 24 that includes a flat surface 26 for receiving input electromagnetic fields 12 that are combined to form a combined input electromagnetic field 14 that is input to the OE2. A second face 6 of the body 24 may include a continuously varying, undulating, or corrugated surface 32. In one example, combined input electromagnetic field 14 passes through the OE2 of FIGS. 6A and 6B and is modified or shaped into output electromagnetic field 18 at output face 16 by the diffractive properties of these OE2s.

[0063] The OE2 portions shown in Figures 6A and 6B are cut-out portions, e.g., small segments, of a larger circular or disc-shaped OE2, although this is not intended to be limiting, as each OE2 described in this disclosure may have any shape deemed appropriate and / or desirable for a particular application, such as, for example, rectangular, circular, or square.

[0064] The illustration of the continuously varying, undulating, or wavy surfaces 32 in Figures 6A and 6B as having the same height in the Z direction in an arc radially centered at the lower right corner of the portion shown in Figures 6A and 6B should not be construed in a limiting sense, as these surfaces 32 can have any suitable and / or desirable periodic and / or non-periodic form of the varying, undulating, or wavy surfaces 32 that is deemed appropriate and / or desirable for a given application. For example, the continuously varying, undulating, or wavy surfaces 32 may vary in height radially as shown in Figures 6A and 6B, may vary as an arc radially centered at the lower right corner of the portion shown in Figures 6A and 6B, or may be a combination thereof. Furthermore, while the heights of the surfaces 32 in Figures 6A and 6B are illustrated as continuously varying, it is contemplated that the heights of these surfaces 32 may vary discontinuously, or may vary in some combination of continuous and discontinuous manners.

[0065] 7, another example OE2 may include a body 24 that includes a flat surface 26 at a first side 4 of the body 24 for receiving input electromagnetic fields 12 that are combined to form a combined input electromagnetic field 14 that is injected into the OE2. A second side 6 of the body 24 may also include a flat surface 33. However, this example OE2 includes different refractive indices n1-n n In one example, the combined input electromagnetic field 14 passes through the OE2 shown in FIG. 7, which has different refractive indices n1 to n n The diffractive properties of the diffractive optical fiber 10 modify or shape the output electromagnetic field 18 at the output face 16 .

[0066] In the orientation shown in FIG. 7, the example OE2 includes strips 38 of the same refractive index n extending in the X and Z directions, while the Y direction includes strips of different refractive indices n1 to n n The strips 38 have different refractive indices n1 to n nThe particular configuration and number of strips 38 in the OE2 of FIG. 7 should not be construed in a limiting sense, as it is contemplated that the strips 38 in the OE2 of FIG. 7 may have any suitable and / or desirable configuration of different refractive indices n.

[0067] 7 including strips 38 is not to be construed in a limiting sense, as it is envisioned that body 24 of OE2 can include configurations of refractive index n that vary in the X, Y, and Z directions, for example, including a checkerboard pattern, a distorted checkerboard pattern in which the grid or array is curved or irregular, an asymmetric checkerboard pattern lacking uniformity in size, spacing, and / or configuration, an irregular checkerboard pattern in which sections (e.g., squares) vary in shape, size, or configuration, and / or a randomized checkerboard pattern in which sections (e.g., squares) are randomly positioned or altered. That is, body 24 can include multiple areas of different refractive index, and each area of ​​different refractive index can extend between first surface 4 and second surface 6 of body 24.

[0068] In one example, the combined input electromagnetic field 14 passes through OE2 of FIG. 7 and is modified or shaped into an output electromagnetic field 18 at output face 16 by the diffractive properties of OE2 of FIG.

[0069] 1A in a non-limiting sense, since it is contemplated that the orientation of each OE2 shown in Figures 2-7 may be reversed, in which case second surface 6 of body 24 may face array of light emitters 8 or combined input electromagnetic field 14, and first surface 4 of body 24 may face output surface 16. Thus, in this disclosure, the terms "first surface" and "second surface" when used in connection with body 24 and / or OE2, should not be construed in a non-limiting sense.

[0070] Having thus described a number of non-limiting example OE2s, a non-limiting example of how to design an example OE2 will now be described with reference to Figures 8A-10B and with continuing reference to all preceding figures.

[0071] Figure 8A shows an example desired (target) intensity pattern or profile 34 of output electromagnetic field 18 at output face 16, which may be located a distance d2, e.g., 5 meters, from OE2. Figure 8B shows an example actual intensity pattern or profile 34' of output electromagnetic field 18 produced by OE2 fabricated in accordance with the following disclosure, at output face 16, which may be located a distance d2, e.g., 5 meters, from OE2. Figures 9A-9B are example cross-sectional views of example target intensity profile 34 and actual intensity profile 34' taken along lines IXA-IXA in Figure 8A and IXB-IXB in Figure 8B, respectively.

[0072] In FIG. 8A, the (target) intensity pattern or profile 34 is a regular angular grid and cos -4 This can be determined by angular intensity scaling of θ, where θ is the polar angle measuring the deviation from the optical axis perpendicular to the plane of the first surface 4 of the OE 2. The angular spacing is set to provide approximately 600 output spots 36 in the actual intensity pattern or profile 34′ shown in FIG.

[0073] As an example, the array 8 of light emitters 10 used to create the actual intensity pattern or profile of Figure 8B is a 1 x 20 array of single-mode light emitters 10 distributed horizontally with 22 micron spacing. In this example, each light emitter 10 has a center wavelength of 1380 nm and a spectral bandwidth of 6 nm. The resulting coherence length is 101 μm (coherence time = 337 fs). The horizontal and vertical divergence half-maximum angles are 11.8 degrees and 19.9 degrees, respectively, with the electromagnetic field polarization oriented along the array axis (i.e., the slow axis of each light emitter 10).

[0074] In this example, the first face 4 of the OE2 is located a distance d1, e.g., 0.56 mm, from the edge or top surface of the light emitter 10. At this distance d1, the fields of view from the individual light emitters 10 at least partially overlap, as shown in Figure 1A by reference numeral 40. The relationship between the array 8 of light emitters 10, the OE2, and the output face 16 is shown schematically in Figure 1A.

[0075] The design of an OE2 occurs in two main parts. In the first part "1" of the design process, the individual electromagnetic fields 12 emitted by the individual optical emitters 10, e.g., edge-emitting lasers, are combined to form a combined input electromagnetic field 14 at or in close proximity to the first face 4 of the OE2. The following describes a method for designing the OE2 (and more specifically its phase transfer function) such that the desired output electromagnetic field 18 is produced at the output face 16 when all the optical emitters 10 pass through the OE2.

[0076] In the first part "1" of the design process, the composite input electromagnetic field 14 injected into the first face 4 of OE2, derived from all of the individual electromagnetic fields 12 emitted by the individual light emitters 10, is determined as follows:

[0077] Step 1A: A location is selected for the first surface 4 of the OE2 relative to the light emitters 10. Without limiting the scope of the present disclosure, the first surface 4 will be selected at a distance d1 to the array 8 of light emitters 10, at which the individual electromagnetic fields 12 emitted by all or substantially all of the individual light emitters 10 substantially overlap, as shown by reference numeral 40 in FIG. 1A. As shown in FIG. 1A, the individual electromagnetic fields 12 at the sides or edges of the first surface 4 of the OE2 may not overlap. The distance d1 may depend on any one or more of the following parameters: the numerical aperture or divergence angle of the individual light emitters 10, the spacing between the individual light emitters 10, and / or the lateral dimension (perpendicular to the optical axis) of the array 8 of light emitters 10. The location of the first face 4 of the OE2 relative to the array 8 of light emitters 10 may be determined by one or more of the following methods: geometric optics, ray tracing, Gaussian beam propagation, or any other method known to those skilled in the art of optics.

[0078] Step 1B: At the first face 4 of the OE2, a first combined input electromagnetic field 14 from the individual electromagnetic fields 12 emitted by all or substantially all of the individual light emitters 10 is determined as follows: For each individual light emitter 10, the complex electromagnetic field 12 of the individual light emitter 10 at each spatial location on the surface of the first face 4 of the OE2 is calculated after adding a phase shift randomly selected between 0 and 2π. This random phase shift is added to accommodate the mutual spatial incoherence of the individual light emitters 10. All combined electromagnetic fields 12 of the individual light emitters 10 at each location on the first face 4 of the OE2 are combined, e.g., added or summed, to form the first combined input electromagnetic field 14.

[0079] Step 1C: Next, after a time delay greater than the coherence time, a second combined input electromagnetic field 14 is calculated in the same manner as the first combined input electromagnetic field 14. The second combined input electromagnetic field 14 is modeled by creating a different set of random phase shifts and applying the different random phase shifts to each of the individual electromagnetic fields 12 emitted by each individual optical emitter 10 into the first face 4 of the OE2, and then combining, e.g., adding or summing, the individual electromagnetic fields 12 emitted by all of the individual optical emitters 10 to form a second combined input electromagnetic field 14 that differs from the first combined input electromagnetic field 14 due to the changed phase relationships between the individual electromagnetic fields 12.

[0080] Step 1D: Next, a first average combined electromagnetic field is determined in both phase and amplitude by combining, e.g., adding or summing, the first and second combined input electromagnetic fields 14 at each location on the first surface 4 of the OE2. However, before this combination occurs, the phases of the first and second combined input electromagnetic fields 14 are “unwrapped” so that the combined input wavefront is continuous. In this disclosure, “unwrapping” refers to a process used to reconstruct the true phases of the individual electromagnetic fields 12 from their wrapped phases. For example, while the phases of the waves of the individual electromagnetic fields 12 can be expressed as angles between π and −π radians, a discontinuity may occur when the phase crosses these boundaries, appearing to “wrap around.” For example, if the phases of the waves of the individual electromagnetic fields 12 gradually increase, the phase may jump from π to −π when crossing the π boundary. This discontinuity is not physical but is a result of the phase being limited to a limited range. "Unwrapping" corrects this by adding multiples of 2π to remove the discontinuity, thereby achieving a continuous phase representation.

[0081] Step 1E: A third combined input electromagnetic field 14 is then calculated in the same manner as the first and second combined input electromagnetic fields 14. A second average combined electromagnetic field is then determined by combining the first, second, and third combined input electromagnetic fields 14 at each location on the first face 4 of the OE2.

[0082] Step 1F: The above process is repeated N times, each time forming a new combined input field and combining each new combined input field with all of the previously determined combined input fields, resulting in an Nth average combined field in the manner described above. The Nth averaged combined field is determined by combining the N combined input fields in both phase and amplitude and averaging them at each location on the first face 4 of the OE2.

[0083] Step 1G: After each iteration, the Nth and (N-1)th average coupled electromagnetic fields are compared. If the difference in phase and amplitude for the Nth and (N-1)th iterations exceeds a predetermined tolerance, the procedure continues. However, if the change is less than the predetermined tolerance, the procedure is considered complete, and the averaged coupled electromagnetic field of all light sources thus determined can be used as the composite input electromagnetic field 14 for the design of OE2.

[0084] 10A-10B show examples of the amplitude and phase of the combined input electromagnetic field 14 used in the design of OE2.

[0085] In the second portion “2” of the design process, the composite input electromagnetic field 14, determined as described above for the first portion “1” of the design process, is used to design OE2, whose amplitude and phase are shown in FIGS. 10A-10B and are then used to design the phase transfer function of OE2 required to produce the desired amplitude, intensity, or intensity distribution of output electromagnetic field 18 at output face 16. The pattern of the amplitude, intensity, or intensity distribution of output electromagnetic field 18 can be defined in angular space or at output face 16 located a distance d2 from OE2. The design of OE2 (and more particularly, the phase transfer function of OE2) can use algorithms well known to those skilled in the art of optical design, such as, but not limited to, the Gerchberg-Saxton iterative Fourier transform algorithm, which is described below. However, it is contemplated that other suitable algorithms can be used in the design of OE2. The detailed iterative design second portion “2” continues as follows:

[0086] Step 2A: A desired target amplitude, intensity, or intensity distribution ("Target") of output electromagnetic field 18 at output face 16 is established, for example, that of FIG. 8A.

[0087] Step 2B: The inverse Fourier transform of the target is calculated to provide a complex field F -1 (Target) is generated.

[0088] Step 2C: The amplitude of the composite input electromagnetic field 14 ("Input") for the design of OE2 determined in Step 1G above is calculated as F -1 By multiplying it by the exponent of the phase of (Target), we obtain the intermediate complex electromagnetic field ("Interim Source").

[0089] Step 2D: The Fourier transform of the "Interim Source" is calculated as F(Interim Source).

[0090] Step 2E: A complex field ("Interim Output") is calculated using the phase of F (Interim Source) and the target amplitude, intensity, or intensity distribution.

[0091] Step 2F: The inverse Fourier transform of the “Interim Output” determined in step 2E is calculated to provide a complex field F -1 (Interim Output) is generated. This is similar to step 2B, except that the current Interim Output (determined in step 2E) is used instead of the Target.

[0092] Step 2G: The amplitude of the composite input electromagnetic field 14 ("Input") for the design of OE2 determined in Step 1G above is calculated based on the F determined in Step 2F. -1 The intermediate complex electromagnetic field ("Interim Source") is determined by multiplying it by the exponent of the phase of the Interim Output ("Interim Output"). This is similar to step 2C, but with F -1 F instead of (Target) -1 The difference is that it uses (Interim Output).

[0093] Step 2H: Repeat steps 2D-2G until the "Interim Output" matches the "Target" within a predetermined desired tolerance.

[0094] Step 2I: Finally, the desired phase of OE2 is now the phase obtained from the phase of the last iteration of the Interim Source. From the desired phase of OE2, the size, shape, and height of the protrusions or posts 28 of OE2 shown in Figures 2-5, the continuously varying thickness of OE2 shown in Figure 6, and / or the varying refractive index of OE2 with a constant height or thickness shown in Figure 7 can be determined.

[0095] As can be seen in Figure 8B, the actual intensity profile produced by OE2 at output face 16 is the same or substantially the same as the target intensity profile at output face 16 shown in Figure 8A. Furthermore, as can be seen, the cross-sections of the example target intensity profile and actual intensity profile shown in Figures 9A-9B are the same or substantially the same.

[0096] The number of light emitters 10 used in this example and the individual divergence characteristics of each mode are strictly for illustrative purposes and should not be construed as limiting the present disclosure.

[0097] One set of differences from the above example may include one or more of the following modifications to the characteristics of the light source:

[0098] Number of light emitters 10.

[0099] Physical configuration of the light emitter 10.

[0100] The divergence characteristics of each individual light emitter 10.

[0101] and / or the wavelength of each individual light emitter 10 .

[0102] Another set of differences may include one or more of the following modifications to the amplitude, intensity, or intensity distribution of the output electromagnetic field 18 generated by OE2 at the output face 16:

[0103] Number of output spots: 36.

[0104] 36 output spot configurations, including pincushion / barrel distortion control.

[0105] Different angular intensity profiles.

[0106] and / or modifying the shape of the output spot 36 (including, for example, correcting anamorphic distortions caused by tiling splitters).

[0107] The design methods and class of devices described above are extended to diffusers and other outputs simply by creating the desired intensity profile at the output face.

[0108] One advantage of the present disclosure is that OE2 can be created at a working distance d1 where the individual input electromagnetic fields 12 overlap or substantially overlap (see 40 in FIG. 1A), which relaxes alignment and design constraints and tolerances and increases flexibility in output pattern design.

[0109] Another advantage over prior art (e.g., structured light generator approaches in which each VCSEL generates only a subset of dots in the form of tiles stitched at an angle through the use of lenses) is that each individual light emitter 10 generates the same or substantially the same output pattern. The input electromagnetic fields 12 generated by all light emitters 10 are substantially overlapping or nearly identical (as shown at 40 in FIG. 1A ). This allows for the overlay of global weighting patterns (e.g., the target intensity profile (e.g., the fourth power of arccosine) in FIG. 8A ) that are not possible with non-overlapping prior art approaches. The inventors have discovered that turning off an individual light emitter 10 leaves the output electromagnetic field 18 unchanged or substantially unchanged, whereas in prior art structured light generators, the “output spot tile” corresponding to the turned-off emitter is lost from the overall output electromagnetic field. However, according to the present disclosure, it is envisioned that two or more light emitters 10 can be turned off without affecting the output electromagnetic field 18, i.e., the output electromagnetic field 18 remains unchanged. Furthermore, prior art structured light generators are constrained by a global focusing lens working distance to provide seamless stitching for a particular light source dimension and splitter parameters. The optical system described in this disclosure allows for a large arbitrary working distance d1 between the array 8 of light emitters 10 and the first surface 4 of the OE2, reducing alignment sensitivity.

[0110] In one non-limiting example of the present disclosure, where the input source is an array 8 of light emitters 10 and the output is a target intensity pattern or profile 34 having a regular angular array of output spots 36, the working distance d1 between the array 8 of light emitters 10 and the first face 4 of the OE2 may be selected to match the size of the angular step between the light emitters 10 to the size of the angular step of the output spots 36 of the target intensity pattern or profile 34 ( FIG. 8A ) at the output face 16. By way of example, the angular distance between adjacent or neighboring light emitters 10 is

number

[0111] Advantages of the optical system and OE2 described herein include:

[0112] The OE 2 is designed to work with two or more light emitters 10 (eg, an array 8 of light emitters 10).

[0113] The electromagnetic fields 12 emitted by the two or more light emitters 10 at least partially overlap each other to form a combined input electromagnetic field 14 at the first face 4 of the OE2.

[0114] OE2 generates an output electromagnetic field 18 from electromagnetic fields 12 launched into OE2 from two or more optical emitters 10.

[0115] The output electromagnetic field 18 generated by OE2 from the combined input electromagnetic field 14 remains unchanged or substantially unchanged when one or more of the light emitters 10 are turned off.

[0116] In use, OE2 creates a desired intensity distribution at output face 16, or a desired angular output intensity distribution from output electromagnetic field 18, with output electromagnetic field 18 generated by OE2 at output face 16 remaining unchanged or substantially unchanged even when one or more of the light emitters 10 are turned off. The electromagnetic field 12 generated by each individual light emitter 10 produces an angular output distribution or spatial output distribution that is closely related to the output distribution created by output electromagnetic field 18. For example, the output intensity distribution of an individual light emitter 10 may differ from that produced from output electromagnetic field 18 in the following ways:

[0117] The power distribution of individual light emitters 10 (e.g., relative to the location of the peak intensity of output electromagnetic field 18 or other spatial reference) may exhibit small angular or lateral displacements, e.g., 0.01°, 0.1°, 1.0°, 1 micron, 10 microns, 100 microns, from the power (intensity) distribution of output electromagnetic field 18.

[0118] The power distribution of the individual light emitters 10 may be similar in general shape except at a given location, and may deviate slightly from the power (intensity) distribution resulting from the output electromagnetic field 18 .

[0119] For a pattern of spots 36, an individual light emitter 10 may produce an output that results in a subset of the total number of rows or columns of spots 36.

[0120] The output spot 36 of each light emitter 10 may be distorted, for example, oversized or undersized and / or anamorphically compressed.

[0121] And / or the output distribution may be affected if one or more individual light emitters 10 stop contributing to the output electromagnetic field 18, in which case the intensity at a given location in the output electromagnetic field 18 at the output face 16 may be reduced by approximately 1 / N, where N is the number of emitters contributing to the combined field.

[0122] Other non-limiting examples or aspects of the present disclosure are described in the exemplary clauses for the following numbered description.

[0123] Clause 1: An optical element (OE) for synthesizing the outputs of an array of light emitters into an output of globally weighted intensity includes a body. The body is configured such that in response to N light emitters emitting N electromagnetic fields that at least partially overlap with each other toward the body to form an input electromagnetic field on a first surface of the body, the body generates an output electromagnetic field on an output surface disposed on a second surface of the body. The body is configured such that the intensity at the output surface of the output electromagnetic field remains invariant or substantially invariant between a first time when the N light emitters are emitting N electromagnetic fields and a second time when M of the N light emitters are emitting M electromagnetic fields, where M < N, N ≧ 3, and M ≧ 2. The intensity or intensity distribution at the output surface of the output electromagnetic field is substantially invariant when each of one or more portions or areas of the output electromagnetic field at the output surface has a decreased intensity at the second time relative to the first time but does not disappear, and the remaining portions or areas of the output electromagnetic field have the same intensity at the first time and the second time.

[0124] Clause 2: The OE according to Clause 1, wherein the intensity of the output electromagnetic field can remain substantially invariant even when N - M of the light emitters stop emitting light, and the change in intensity in one or more portions or areas of the output electromagnetic field is about (N - M) / N%.

[0125] Clause 3: The OE according to Clause 1 or 2, wherein the intensity of the output electromagnetic field remains substantially invariant when the intensity distribution of the output electromagnetic field changes between 0.1% and 10% at the second time when M of the N light emitters are emitting light relative to the first time when the N light emitters are emitting light.

[0126] Clause 4: An OE as described in any one of clauses 1 to 3, wherein the body may be comprised of a single, integrated body including at least one of a flat or non-flat surface on a first side of the body and a flat or non-flat surface on a second side of the body.

[0127] Clause 5: An OE described in any one of clauses 1 to 4, wherein at least one non-flat surface may comprise an array of protrusions, pillars, or extrusions, or a continuously and / or discontinuously varying, undulating, or wavy surface.

[0128] Clause 6: The OE of any one of clauses 1-5, wherein each protrusion, post, or extrusion may have a cylindrical shape and / or a circular cross-section.

[0129] Clause 7: The OE of any one of clauses 1-6, wherein the protrusions, posts, or extrusions may be spaced apart from one another.

[0130] Clause 8: The OE of any one of clauses 1-7, wherein the array of protrusions, posts, or extrusions can include protrusions, posts, or extrusions having different diameters.

[0131] Clause 9: The OE of any one of clauses 1-8, wherein the protrusions, posts, or extrusions may all have the same height.

[0132] Clause 10: The OE of any one of clauses 1-9, wherein the protrusions, posts, or extrusions may have different heights.

[0133] Clause 11: The OE of any one of clauses 1-10, wherein each protrusion, post, or extrusion may have a square or rectangular cross-section.

[0134] Clause 12: The OE of any one of clauses 1-11, wherein the array of protrusions, posts, or extrusions can include protrusions, posts, or extrusions having different heights.

[0135] Clause 13: The OE according to any one of Clauses 1 to 12, wherein the array of protrusions, columnar parts, or extrusions can be formed by etching a block of OE material.

[0136] Clause 14: The OE according to any one of Clauses 1 to 13, wherein the body can include a plurality of areas with different refractive indices, and each area with a different refractive index can extend between the first surface and the second surface of the body.

[0137] Clause 15: The OE according to any one of Clauses 1 to 14, wherein the body can include a flat first surface and a flat second surface.

[0138] Clause 16. An optical element (OE) having a first surface and a second surface, and an array of optical emitters arranged and operable to radiate input electromagnetic fields that at least partially overlap each other onto the first surface of the OE to form a combined input electromagnetic field on the first surface of the OE. According to the combined input electromagnetic field, the OE generates an output electromagnetic field on an output surface arranged on the second surface of the OE, and the intensity or intensity distribution of the output electromagnetic field on the output surface remains unchanged or substantially unchanged between a first time when all of the optical emitters of the array of optical emitters are emitting the input electromagnetic field and a second time when one or a plurality of subsets of the optical emitters of the array of optical emitters are not emitting the input electromagnetic field, and the intensity of the output electromagnetic field remains substantially unchanged when one or a plurality of portions or areas of the output electromagnetic field are continuously irradiated with a reduced intensity at the second time relative to the first time. An optical system.

[0139] Clause 17: The optical system according to Clause 16, wherein the first surface of the OE and the array of optical emitters are arranged at a distance d1 from each other, and the second surface of the OE and the output surface are arranged at a distance d2 from each other, and d1 < d2.

[0140] Clause 18: The optical system according to Clause 16, wherein the first surface of the OE includes a flat or non-flat surface, and the second surface of the OE includes a flat or non-flat surface.

[0141] Clause 19: An optical system as described in Clause 18, wherein each non-flat surface comprises a plurality of protrusions, columns, or extrusions of the same or different heights, or an undulating or wavy surface that varies continuously and / or discontinuously.

[0142] Clause 20: The optical system of clause 19, wherein the OE includes a plurality of areas with different refractive indices.

[0143] While the present disclosure has been described in detail for purposes of illustration, based on what are presently considered to be the most practical and preferred embodiments, it should be understood that such details are for illustrative purposes only, and that the present disclosure is not limited to the disclosed embodiments, but on the contrary, is intended to cover modifications and equivalent arrangements within the spirit and scope of the appended claims. For example, it should be understood that the present disclosure contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment. [Explanation of symbols]

[0144] 2 Optical Elements, OE 4. First Side 6 Second Side 8. Array 10 Light Emitter 12 Input Electromagnetic Field 14 Combined input electromagnetic field 16 Output Surface 18 Output Electromagnetic Field 24 Main Unit 25 base 26 Flat Surface 28 Projections or columns 30 Longitudinal axis 32 Surface 34 Target Intensity Pattern or Profile 34' Actual Intensity Pattern or Profile 36 Spots 38 Strip

Claims

1. an optical element (OE) for combining the outputs of an array of light emitters into a globally weighted intensity output, a body configured to generate an output electromagnetic field at an output surface disposed on a second surface of the body in response to N optical emitters emitting N electromagnetic fields that at least partially overlap one another toward the body to form an input electromagnetic field at a first surface of the body; the body is configured such that an intensity at the output face of the output electromagnetic field remains unchanged or substantially unchanged between a first time when the N light emitters are emitting the N electromagnetic fields and a second time when M of the N light emitters are emitting M electromagnetic fields, where M<N, N≧3, and M≧2; An optical element (OE), wherein the intensity of the output electromagnetic field at the output surface remains substantially unchanged when one or more portions or areas of the output electromagnetic field at the output surface each have a reduced intensity at the second time relative to the first time but do not disappear, and remaining portions or areas of the output electromagnetic field have the same intensity at the first time and the second time.

2. 2. The OE of claim 1, wherein an intensity of the output electromagnetic field remains substantially unchanged when N-M of the light emitters cease emitting light, and wherein the change in intensity in the one or more portions or areas of the output electromagnetic field is about (N-M) / N %.

3. 2. The OE of claim 1, wherein the intensity of the output electromagnetic field remains substantially unchanged when the intensity distribution of the output electromagnetic field changes between 0.1% and 10% in the second time that the M of the N light emitters are emitting light relative to the first time that the N light emitters are emitting light.

4. The body includes: a flat or non-flat surface of the first face of the body; and The OE of claim 1 , wherein the OE is comprised of a single, integral body including at least one of a flat and a non-flat surface on the second side of the body.

5. One or both of the non-planar surfaces may be: an array of protrusions, posts, or extrusions; 5. An OE according to claim 4, comprising a continuously and / or discontinuously varying, undulating or wavy surface.

6. 6. The OE of claim 5, wherein each protrusion, post, or extrusion has a cylindrical shape and / or a circular cross section.

7. The OE of claim 6 , wherein the protrusions, posts, or extrusions are spaced apart from one another.

8. 8. The OE of claim 7, wherein the array of protrusions, posts, or extrusions comprises protrusions, posts, or extrusions having different diameters.

9. The OE of claim 8 , wherein the protrusions, posts, or extrusions all have the same height.

10. The OE of claim 7 , wherein the protrusions, posts, or extrusions have different heights.

11. 6. The OE of claim 5, wherein each protrusion, post, or extrusion has a square or rectangular cross-section.

12. 12. The OE of claim 11, wherein the array of protrusions, posts, or extrusions comprises protrusions, posts, or extrusions having different heights.

13. 6. The OE of claim 5, wherein the array of protrusions, posts, or extrusions is formed by etching a block of OE material.

14. the body includes a plurality of areas with different refractive indices; Each area of ​​different refractive index extends between the first surface and the second surface of the body.

2. The OE of claim 1.

15. The OE of claim 14 , wherein the body includes a planar first surface and a planar second surface.

16. an optical element (OE) having a first surface and a second surface; an array of light emitters arranged and operable to emit at least partially overlapping input electromagnetic fields onto the first surface of the OE to form a composite input electromagnetic field at the first surface of the OE; In response to the combined input electromagnetic fields, the OE generates an output electromagnetic field at an output surface disposed on the second surface of the OE; an intensity or intensity distribution at the output face of the output electromagnetic field remains unchanged or substantially unchanged between a first time when all of the light emitters of the array of light emitters are emitting the input electromagnetic field and a second time when one or more subsets of the light emitters of the array of light emitters are not emitting the input electromagnetic field; the intensity of the output electromagnetic field remains substantially unchanged when one or more portions or areas of the output electromagnetic field continue to be illuminated at a reduced intensity at the second time relative to the first time. optical system.

17. the first surface of the OE and the array of light emitters are disposed at a distance d1 from each other; the second surface and the output surface of the OE are disposed at a distance d2 from each other; d1<d2, 17. The optical system of claim 16.

18. the first surface of the OE includes a flat or non-flat surface; the second surface of the OE includes a flat or non-flat surface; 17. The optical system of claim 16.

19. Each non-planar surface is a plurality of protrusions, posts, or extrusions of the same or different heights, with adjacent protrusions, posts, or extrusions touching or spaced apart from one another; or 19. The optical system of claim 18, comprising a continuously and / or discontinuously varying, undulating or wavy surface.

20. The optical system of claim 16 , wherein the OE includes multiple areas of different refractive index.

Images