Optical components to polarizing beam-splitter alignment

Abstract

Methods and apparatuses for aligning an optical waveguide with a polarizing beam-splitter (PBS) and for aligning a reflective lens with the PBS once it is aligned with the optical waveguide are described herein. The methods involve various optical techniques that allow for precise location and angular alignment between the respective components. By using the described techniques, misalignment may be mitigated thereby reducing image distortion and poor angular distribution of light and increasing light for beams that are coupled out of the optical waveguide.

Description

Docket: SSMP 45896 (Lumus 00202-3US)OPTICAL COMPONENTS TO POLARIZING BEAM-SPLITTER ALIGNMENTCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The subject application claims the benefit of U.S. Provisional Application No.63 / 903,139, filed on October 21, 2025, U.S. Provisional Application No. 63 / 854,288, filed on July 30, 2025 and U.S. Provisional Application No. 63 / 762,017, filed on February 23, 2025, the entire disclosure of each of which is incorporated herein by this reference.FIELD

[0002] This disclosure is directed to optical waveguides, such as those used in near-eye displays.BACKGROUND

[0003] Optical waveguides are implemented in a variety of environments to manipulate and direct beams of light. For example, many near-eye displays (NEDs) and heads-up displays (HUDs) (e.g., those used for virtual reality (VR) or augmented reality (AR) applications) utilize an optical waveguide to direct beams generated by a projector to a user’s eye. The beams are injected into the optical waveguide via an aperture, propagate through the optical waveguide via total internal reflection (TIR), and exit the optical waveguide towards the user’s eye (e.g., an eye box) via one or more coupling-out elements.

[0004] Some projection systems include a polarizing beam-splitter (PBS) coupled to an optical waveguide, in which an incident beam (e.g., from a projector) is split into two beams via the PBS that are subsequently recombined to enter the optical waveguide. Misalignment between optical components of such systems can result in image distortion, reduced brightness, and poor angular distribution of light, thereby affecting the overall user experience. It is often challenging to achieve precise alignment and optimal performance due to the complexity of the optical components. Such systems typically require intricate assembly processes and precise calibration, and complicated alignment apparatuses to ensure that light paths are correctly aligned, which can lead to increased manufacturing costs and potential performance inconsistencies.Docket: SSMP 45896 (Lumus 00202-3US)SUMMARY

[0005] A method of aligning an optical waveguide to a PBS is described herein. The method includes orienting the optical waveguide relative to the PBS such that an intersection of a major surface and an end surface of the optical waveguide is proximate an intersection of a first lens surface and an output aperture surface of the PBS. The method also includes projecting a light beam into the PBS such that it exits the output aperture surface of the PBS, enters the end surface of the optical waveguide, and exits the optical waveguide via a plurality of partially reflecting facets. The method further includes monitoring, via a light imager, parallelism between first and second portions of the light beam that have exited the optical waveguide. The method also includes moving the optical waveguide relative to the PBS and, responsive to determining, via the light imager, that the first and second portions of the light beam that have exited the optical waveguide are parallel and, preferably, coherently-coplanar, securing the optical waveguide to the PBS.

[0006] Another method of aligning an optical waveguide to a PBS is also described herein. The method includes orienting the optical waveguide relative to the PBS such that an intersection of a major surface and a coupling-in mirror of the optical waveguide is proximate an intersection of a lens surface and an output aperture surface of the PBS. The method also includes projecting a light beam into the PBS such that it exits the output aperture surface of the PBS, enters the major surface of the optical waveguide, reflects off the coupling-in mirror, and exits the optical waveguide via a plurality of partially reflecting facets. The method further includes monitoring, via a light imager, parallelism between first and second portions of the light beam that have exited the optical waveguide. The method also includes moving the optical waveguide relative to the PBS and, responsive to determining, via the light imager, that the first and second portions of the light beam that have exited the optical waveguide are parallel, securing the optical waveguide to the PBS.

[0007] Yet another method of aligning an optical waveguide to a PBS is also described herein. The method includes orienting the optical waveguide relative to the PBS such that an intersection of a major surface and an end surface of the optical waveguide is proximate an intersection of aDocket: SSMP 45896 (Lumus 00202-3US)lens surface and an output aperture surface of the PBS. The method also includes projecting, via an auto-collimator, first and second portions of a light beam onto the major surface and the lens surface, respectively. The method further includes monitoring, via the auto-collimator, parallelism between reflections of the first and second portions of the light beam. The method also includes moving the optical waveguide relative to the PBS and, responsive to determining, via the auto-collimator, that the reflections of the first and second portions of the light beam that have exited the optical waveguide are parallel, securing the optical waveguide to the PBS.

[0008] Yet another method of aligning an optical waveguide to a PBS is also described herein. The method includes orienting the optical waveguide relative to the PBS such that an intersection of a major surface and an end surface of the optical waveguide is proximate an intersection of a first lens surface and an output aperture surface of the PBS. The method also includes placing a slab proximate an interface between the optical waveguide and the PBS such that the slab is in contact with the major surface of the optical waveguide and the lens surface of the PBS. The method further includes projecting, via an auto-collimator, first, second, and third portions of a light beam onto the major surface, the slab, and the lens surface, respectively. The method also includes monitoring, via the auto-collimator, parallelism between reflections of the first, second, and third portions of the light beam reflected by the major surface, the slab, and the lens surface, respectively. The method further includes moving the optical waveguide relative to the PBS and, responsive to determining, via the auto-collimator, that the reflections of the first, second, and third portions of the light beam reflected by the major surface, the slab, and the lens surface, respectively, are parallel, securing the optical waveguide to the PBS.

[0009] A method of aligning a reflective lens to an assembly of a PBS, an optical waveguide coupled with an output aperture surface of the PBS, and a first reflective lens coupled with a first lens surface of the PBS is also described herein. The method includes orienting the second reflective lens proximate a second lens face of the assembly of the PBS, the optical waveguide coupled with an output aperture surface of the PBS, and the first reflective lens coupled with a first lens surface of the PBS. The method also includes projecting a light beam into the PBS such that a first portion of the light beam passes through a splitting component of the PBS, is reflected off the first reflecting lens, and is reflected off the splitting component to exit the outputDocket: SSMP 45896 (Lumus 00202-3US)aperture surface of the PBS and a second portion of the other light beam is reflected by the splitting component, is reflected by the second reflecting lens, and passes through the splitting component to exit the output aperture surface of the PBS. The first and second portions of the light beam enter an end surface of the optical waveguide and exit the optical waveguide via the plurality of partially reflecting facets. The method further includes monitoring, via a light imager, parallelism between the first and second portions of the light beam that have exited the optical waveguide. The method also includes translating the second reflecting lens relative to the PBS and, responsive to determining, via the light imager, that the first and second portions of the light beam that have exited the optical waveguide are parallel, securing the second reflecting lens to the PBS.

[0010] Alignment apparatuses are also described herein. The alignment apparatuses are configured to perform at least portions of the above methods.

[0011] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. In the drawings, like reference numbers indicate identical or functionally similar elements.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 illustrates an example of a near-eye display with optical components in accordance with this disclosure.

[0013] FIG. 2 illustrates an example of an optical assembly in accordance with this disclosure.

[0014] FIG. 3 illustrates example alignments of the optical assembly of FIG. 2 in accordance with this disclosure.

[0015] FIG. 4A illustrates an example of a misalignment between an optical waveguide and PBS from the optical assembly of FIG. 2 and components of an apparatus usable to measure the alignment in accordance with this disclosure.Docket: SSMP 45896 (Lumus 00202-3US)

[0016] FIG. 4B illustrates an example of correcting the misalignment of FIG. 4A and the components of FIG. 4A in accordance with this disclosure.

[0017] FIG. 5 illustrates an example of a proper alignment between the optical waveguide and PBS from the optical assembly of FIG. 2 and components of another apparatus usable to measure the alignment in accordance with this disclosure.

[0018] FIG. 6 illustrates the example of FIG. 5 with an example shutter system in accordance with this disclosure.

[0019] FIG. 7 illustrates an example of a proper alignment between the optical waveguide and PBS from the optical assembly of FIG. 2 and components of yet another apparatus usable to measure the alignment in accordance with this disclosure.

[0020] FIG. 8 illustrates an example of a proper alignment between the optical waveguide and PBS from the optical assembly of FIG. 2 and components of yet another apparatus usable to measure the alignment in accordance with this disclosure.

[0021] FIG. 9A illustrates an example of an angular and displacement misalignment between the optical waveguide and PBS from the optical assembly of FIG. 2 and components of yet another apparatus usable to measure the alignment in accordance with this disclosure.

[0022] FIG. 9B illustrates an example of an output from the apparatus of FIG. 9A in accordance with this disclosure.

[0023] FIG. 10A illustrates an example of an angular alignment and a displacement misalignment between the optical waveguide and PBS from the optical assembly of FIG. 2 and the components of FIGS. 9 A and 9B in accordance with this disclosure.

[0024] FIG. 10B illustrates an example of an output from the apparatus of FIG. 10A in accordance with this disclosure.Docket: SSMP 45896 (Lumus 00202-3US)

[0025] FIG. 11 A illustrates an example of proper alignment between the optical waveguide and PBS from the optical assembly of FIG. 2 and the components of FIGS. 9A, 9B, 10A, and 10B in accordance with this disclosure.

[0026] FIG. 1 IB illustrates an example of an output from the apparatus of FIG. 11 A in accordance with this disclosure.

[0027] FIG. 12A illustrates an example of a misalignment between a second reflective lens and the PBS of FIG. 2 and components of an apparatus usable to measure the alignment in accordance with this disclosure.

[0028] FIG. 12B illustrates an example of correcting the misalignment of FIG. 12A and the components of FIG. 12A in accordance with this disclosure.

[0029] FIG. 13 illustrates another example of an optical assembly in accordance with this disclosure.

[0030] FIG. 14 illustrates example necessary alignments of the optical assembly of FIG. 13 in accordance with this disclosure.

[0031] FIG. 15 illustrates an example of a proper alignment between the optical waveguide and PBS from the optical assembly of FIG. 13 and components of an apparatus usable to measure the alignment in accordance with this disclosure.

[0032] FIG. 16 illustrates an example of a proper alignment between the optical waveguide and PBS from the optical assembly of FIG. 13 and components of another apparatus usable to measure the alignment in accordance with this disclosure.

[0033] FIG. 17 illustrates the example of FIG. 16 with an example shutter system in accordance with this disclosure.

[0034] FIG. 18 illustrates an example of a proper alignment between a second reflective lens and the PBS of FIG. 13 and components of an apparatus usable to measure the alignment in accordance with this disclosure.Docket: SSMP 45896 (Lumus 00202-3US)

[0035] FIG. 19 illustrates an example of a method of aligning the optical waveguide with the PBS of FIG. 2 in accordance with this disclosure.

[0036] FIG. 20 illustrates an example of a method of aligning the optical waveguide with the PBS of FIG. 13 in accordance with this disclosure.

[0037] FIG. 21 illustrates an example of another method of aligning the optical waveguide with the PBS of FIG. 2 in accordance with this disclosure.

[0038] FIG. 22 illustrates an example of yet another method of aligning the optical waveguide with the PBS of FIG. 2 in accordance with this disclosure.

[0039] FIG. 23 illustrates an example of a method of aligning the second reflective lens and the PBS of FIG. 2 or FIG. 13 in accordance with this disclosure.

[0040] FIG. 24 illustrates an example of an apparatus usable to perform any of the alignments in accordance with this disclosure.DETAILED DESCRIPTIONOverview

[0041] Misalignment between optical components of optical systems that include PBSs coupled to optical waveguides can result in image distortion, reduced brightness, and poor angular distribution of light, thereby affecting the overall user experience. It is often challenging to achieve precise alignment and optimal performance due to the complexity of the optical components.

[0042] Methods of, and apparatuses for, aligning an optical waveguide with a PBS and for aligning a reflective lens with the PBS once it is aligned with the optical waveguide are described herein. The methods involve various optical techniques that allow for precise location and angular alignment between the respective components.Docket: SSMP 45896 (Lumus 00202-3US)

[0043] By using the described techniques / apparatuses, misalignment may be mitigated thereby reducing image distortion and poor angular distribution of light and increasing light for beams that are coupled out of the optical waveguide. Furthermore, some of the apparatuses may be used for multiple alignments, thereby reducing time and / or cost of manufacturing.

[0044] In the following description, numerous specific details are set forth, such as particular structures, components, materials, dimensions, processing steps and techniques, in order to provide an understanding of the various embodiments of the present application. However, it will be appreciated by one of ordinary skill in the art that the various embodiments of the present application may be practiced without these specific details. In other instances, well-known structures or processing steps have not been described in detail in order to avoid obscuring the present application.Example Near-Eye Display

[0045] FIG. 1 illustrates an example of a near-eye display 100 with an optical waveguide 102 in accordance with this disclosure. The near-eye display 100 is illustrated as a pair of eyeglasses (e.g., augmented reality glasses); however, the near-eye display 100 may take other forms without departing from the scope of this disclosure (e.g., HUD, single eye glass, monocle).

[0046] The near-eye display 100 includes a frame 104, the optical waveguide 102, a projector 106, and a PBS assembly 112 between the projector 106 and the optical waveguide 102. The optical waveguide 102 and / or the projector 106 may be supported by the frame 104. The frame 104 may be configured to support the optical waveguide 102 on a user’s head such that the optical waveguide 102 is in front of an eye of the user.

[0047] The projector 106 is configured to produce light beams (e.g., those corresponding to images) for injection into the optical waveguide 102. The beams are injected into the optical waveguide 102 via the PBS assembly 112.

[0048] The optical waveguide 102 includes two major surfaces that are flat and parallel to one another and configured to cause the injected beams from the projector 106 to reflectDocket: SSMP 45896 (Lumus 00202-3US)therebetween due to total internal reflection (TIR). The optical waveguide 102 includes a first region 108 that includes a set of first facets (not shown) and a second region 110 that includes a set of second facets (not shown). The first region 108 (e.g., the set of first facets) is configured to expand the beams in the Y -dimension while also redirecting the beams in the X-dimension towards the second region 110. The second region 110 (e.g., the set of second facets) is configured to expand the beams in the X-dimension while also redirecting the beams out of the optical waveguide 102 in the Z-dimension (e.g., couples the beams out of the optical waveguide 102). The facets are described further below.

[0049] It should be noted that the illustrated example has another optical waveguide, another projector, and another PBS assembly (e.g., to the left of the optical waveguide 102 and projector 106). As the other waveguide and projector may be similar to the optical waveguide 102 and the projector 106, respectively, those will not be discussed herein. For example, there may be a left and a right optical waveguide (e.g., for left and right eyes of a user) with corresponding projectors. Furthermore, the projector 106 may be configured to supply beams for injection into both optical waveguides. Accordingly, the configuration of the near-eye display 100 may vary without departing from the scope of this disclosure.Example End-Surface Input Optical Assembly

[0050] FIG. 2 illustrates an example of an optical assembly 200 including the projector 106, the PBS assembly 112, and the optical waveguide 102. The projector 106 is configured to produce one or more light beams 202. Only one light beam 202 is shown for simplicity. The light beam 202 may pass through a field lens 204 before entering a PBS 206.

[0051] The PBS 206 includes a splitting component 208 configured to split the light beam 202 into two polarized beams (shown as dashed and dot / dashed lines). A first of the polarized beams continues in a same direction as the light beam 202 to a first reflecting lens 210, is reflected by the first reflecting lens 210 back to the splitting component 208, and is reflected by the splitting component 208 to exit the PBS 206 and enter the optical waveguide 102. Depending upon a configuration of the PBS 206, an alignment block 212 may be disposed between the PBS 206 and the first reflecting lens 210. A second of the polarized beams is reflected by the splittingDocket: SSMP 45896 (Lumus 00202-3US)component 208 to a second reflecting lens 214, is reflected by the second reflecting lens 214 back through the splitting component 208 to exit the PBS 206 and enter the optical waveguide 102. For the purposes of this disclosure, the PBS 206 may be a include the field lens 204 and / or the alignment block 212 or may be a separate component. Along similar lines, the PBS assembly 112 may include the PBS 206, the first reflecting lens 210, and the second reflecting lens 214. Groupings of the components may change without departing from the scope of this disclosure.

[0052] A first waveplate (e.g., X / 4 waveplate) may be disposed between the first reflecting lens 210 and the PBS 206 to ensure that returning polarization is orthogonal such that the beam can enter the optical waveguide 102. Similarly, a second waveplate (e.g., X / 4 waveplate) may be disposed between the second reflecting lens 214 and the PBS 206 to ensure that returning polarization is orthogonal such that the beam can enter the optical waveguide 102. The waveplates are not shown for clarity.

[0053] Once the light beam 202 (e.g., polarized portions thereof) has exited the PBS 206, it enters the optical waveguide 102 (shown as a single beam for clarity). The optical waveguide 102 includes major surfaces 216 (e.g., major surface 216a and major surface 216b) that are flat and parallel to one another. The light beam 202 reflects between the major surfaces 216 due to total-internal-reflection (TIR).

[0054] The optical waveguide 102 includes a coupling-out region 218 including a plurality of facets. The facets are parallel to one another and formed of respective partially reflective optical elements or surfaces. An end facet (e.g., the far left in the illustrated example) may be fully reflective. As the light beam 202 propagates through the optical waveguide 102 via TIR, it hits each facet. Each facet partially reflects the light beam 202 such that it exits the optical waveguide 102 via one of the major surfaces 216 (e.g., to a user’s eye).

[0055] Only the facets of the coupling-out region 218 are shown. There may be another set of facets between the coupling-out region 218 and the PBS 206. For example, the other set of facets may expand the light beam 202 in a first dimension, while the facets of the coupling-out region may expand the light beam 202 in a second dimension. The configuration of the facets within the optical waveguide 102 may vary without departing from the scope of this disclosure.Docket: SSMP 45896 (Lumus 00202-3US)

[0056] FIG. 3 illustrates example alignments of the optical assembly 200 to produce quality images. The projector 106 has been removed as it may not be necessary for some of the alignment procedures; however, it may be attached without departing from the scope of this disclosure.

[0057] The PBS 206 includes a first lens surface 300, a second lens surface 302, and an output aperture surface 304. The first lens surface 300 is proximate the first reflecting lens 210, and the second lens surface 302 is proximate the second reflecting lens 214. Depending on configuration, the alignment block 212 may be attached between the first reflecting lens 210 and the first lens surface 300 (e.g., as illustrated). Furthermore, a second alignment block may be attached between the second reflecting lens 214 and the second lens surface 302 (e.g., for different geometry of the PBS 206). The output aperture surface 304 is a surface through which light beams exit the PBS 206. Once the light beams have exited, the light beams enter the optical waveguide 102 via an end surface 306.

[0058] In the optical assembly 200, two alignments may be required to achieve good optical performance. The first alignment is between the PBS 206 and the optical waveguide 102. For the first alignment, the major surface 216a of the optical waveguide 102 should be parallel to the first lens surface 300. Furthermore, the major surface 216a of the optical waveguide 102 should be at a same level (e.g., coplanar) or slightly above the first lens surface 300 (e.g., up in the illustrated example).

[0059] The second alignment is between the PBS 206 and the second reflecting lens 214. For the second alignment, the second reflecting lens 214 may be translated along the second lens surface 302. The second alignment may be performed after the first alignment. That is, the optical waveguide 102 may be aligned / attached to the PBS 206 when the second alignment occurs. Also, the first reflecting lens 210 is coupled with the PBS 206 (via the alignment block 212) prior to the second alignment. Depending upon implementation, the field lens 204 and / or the projector 106 may also be coupled to the PBS 206 for the second alignment. In an alternate implementation, the second reflecting lens 214 may be attached to the PBS 206 prior to theDocket: SSMP 45896 (Lumus 00202-3US)second alignment, and the second alignment may involve aligning the first reflecting lens 210 (e.g., along a surface of the alignment block 212 in the illustrated example).

[0060] The two alignments may be performed while adhesives disposed between the respective interfaces are un-cured. The adhesive may allow for light beams to propagate therethrough while also allowing for, as long as the adhesive is not cured, relative movement between the optical waveguide 102 and the PBS 206 and / or between the PBS 206 and the second reflecting lens 214. For example, an adhesive may be disposed between the PBS 206 and the optical waveguide 102 and cured after the first alignment. Similarly, the adhesive (or another adhesive) may be disposed between the PBS 206 and the second reflecting lens 214 and cured after the second alignment. The adhesive may, for example, be a UV-cure adhesive, and curing may involve applying a UV-light to the adhesive. The adhesive may allow for the light beam 202 to propagate therethrough while also allowing for, as long as the adhesive is not cured, relative movement between the optical waveguide 102 and the PBS 206.

[0061] FIG. 4A illustrates an example of a misalignment between the optical waveguide 102 and the PBS 206 of the optical assembly 200. To measure the misalignment, an apparatus may comprise a light source and two imagers. The light source produces the light beam 202 that is split by the splitting component 208 (only the portion that passes through the splitting component 208 is shown as the other portion exits the PBS 206). The portion of the light beam 202 is reflected by the first reflecting lens 210, is reflected by the splitting component 208, exits the PBS 206, enters the optical waveguide 102, and is coupled out via the coupling-out region 218. The light beam 202 may be produced by the projector 106 if it is attached, or it may be produced by a different source. The light beam 202 has a width that is represented by the two dashed lines. A portion of the light beam 202 is reflected by the first lens surface 300 prior to exiting the PBS 206. To illustrate, the relative portions of the light beam 202 are shown as two beams. One of the beams is reflected directly from the splitting component 208 to exit the PBS 206, while another of the beams is reflected off the first lens surface 300 prior to exiting the PBS 206. Because the first lens surface 300 is not parallel with the major surface 216a, the beams are not parallel. Furthermore, if the first lens surface 300 is not coplanar with the major surface 216a, the beams are not coherently constructive.Docket: SSMP 45896 (Lumus 00202-3US)

[0062] A light imager 402 (e.g., camera) is configured to receive the light beam 202 as it exits the optical waveguide 102 via the coupling-out region 218. In the illustrated example, only a single facet of the coupling-out region 218 is shown. The light imager 402 may be configured to receive the light beam 202 from any number of the facets of the coupling-out region 218.Because of the misalignment, the two beams (e.g., portions of the light beam 202) are not parallel. The light imager 402 may be configured to detect the non-parallelism to determine an amount of the angular misalignment.

[0063] An interface imager 404 (e.g., camera or interferometer) is configured to monitor a height difference between the first lens surface 300 and the major surface 216a. The interface imager 404 may be similar to the light imager 402 or configured differently. To measure the height difference, the interface imager 404 may be disposed on a side of the interface (e.g., facing into or out of the page). The interface imager 404 is shown below the interface for clarity. If the interface imager 404 is implemented as an interferometer (e.g., a white-light interferometer), it may be disposed underneath the interface, as illustrated.

[0064] FIG. 4B illustrates an example of an alignment between the optical waveguide 102 and the PBS 206 of the optical assembly 200. The alignment may involve a correction from the example of FIG. 4A. To do so, a movement system of the apparatus (not shown) may manipulate the optical waveguide 102 and / or the PBS 206.

[0065] Using the same setup as FIG. 4A, the light imager 402 may be used to determine when the beams are parallel. The interface imager 404 may be used to determine that the major surface 216a is at a same level or slightly above (e.g., within a threshold distance such as 0.1 micron) of the first lens surface 300.

[0066] When both conditions are true (e.g., parallel beams detected by the light imager 402 and the distance detected by the interface imager is within the threshold distance), the adhesive disposed between the optical waveguide 102 and the PBS 206 may be cured. For example, if the adhesive is an ultraviolet (UV) cure adhesive, a UV light of the apparatus may be used to cure the adhesive. If the adhesive is a non-UV cure adhesive, the optical waveguide 102 and the PBS 206 may be held in place until it cures.Docket: SSMP 45896 (Lumus 00202-3US)

[0067] It should be noted that the second reflecting lens 214 may be coupled with the PBS 206 without the first reflecting lens 210 being coupled with the PBS 206. Similar results may be achieved by switching which of the reflecting lenses are attached to the PBS 206.

[0068] FIG. 5 illustrates another example of an alignment between the optical waveguide 102 and the PBS 206 from the optical assembly 200. The apparatus is similar to that of FIGS. 4A and 4B, except that a collimated light beam 500 (e.g., produced by a collimated light source 502) is injected into the PBS 206 via the second lens surface 302. The collimated light source 502 may be any light source configured to emit the collimated light beam 500. Similar to FIGS. 4A and 4B, a portion of the collimated light beam 500 is reflected by the first lens surface 300 prior to exiting the PBS 206 while another portion of the collimated light beam 500 exits the PBS 206 directly.

[0069] The alignment process is similar to that of FIG. 4B. That is, the light imager 402 may be used to determine when the beams are parallel. The interface imager 404 may be used to determine when the surfaces of the interface are within the threshold distance of each other. When the two conditions are met (e.g., during relative movement between the optical waveguide 102 and the PBS 206), the interface between the optical waveguide 102 and the PBS 206 may be secured (e.g., the adhesive cured). The misalignment is not shown but would involve nonparallel beams and / or offset surfaces.

[0070] In some implementations, the collimated light beam 500 may be injected through the first lens surface 300 (e.g., via the alignment block 212). Similar results may be achieved by switching which direction the collimated light beam 500 enters the PBS 206. Furthermore, more or less components may be attached to the PBS 206 for this implementation. As an example, the field lens 204 and / or the alignment block 212 may not be present for the alignment. However, having the alignment block 212 attached may allow for the light to enter perpendicularly and mitigate dispersion of the beams. Furthermore, the projector 106 and / or one of the reflecting lenses (e.g., the first reflecting lens 210) may be attached to the PBS 206 without departing from the scope of this disclosure.Docket: SSMP 45896 (Lumus 00202-3US)

[0071] FIG. 6 illustrates the example of FIG. 5 with an example shutter system. The example shutter system may include one or more shutters 600 configured to block respective portions of the collimated light beam 500. For example, because it may be difficult for the light imager 402 (or a user) to determine parallelism between the beams, portions of the collimated light beam 500 may be blocked sequentially to produce two images. The two images may be used to better and / or more easily determine parallelism between the beams.

[0072] FIG. 7 illustrates another example of an alignment between the optical waveguide 102 and the PBS 206 from the optical assembly 200. The apparatus in this implementation uses the interface imager 404 to determine the height difference between the first lens surface 300 and the major surface 216a. Instead of projecting light through the PBS 206; however, an autocollimator 700 is used to project beams or portions of a beam onto the first lens surface 300 and the major surface 216a. Reflections from those surfaces may be monitored by the autocollimator 700 for parallelism. When the two conditions are met (e.g., during relative movement between the optical waveguide 102 and the PBS 206), the interface between the optical waveguide 102 and the PBS 206 may be secured (e.g., the adhesive cured). The misalignment is not shown but would involve non-parallel beams detected by the auto-collimator 700 and / or offset surfaces determined by the interface imager 404.

[0073] This apparatus / implementation allows for a flexible manufacturing path. For example, only the PBS 206 and the optical waveguide 102 are needed to perform the alignment. Other components that may ultimately be coupled with the PBS 206 (e.g., the lenses, the projector 106, etc.) may be attached prior to or after the alignment, or some combination thereof.

[0074] FIG. 8 illustrates another example of an alignment between the optical waveguide 102 and the PBS 206 from the optical assembly 200. The apparatus in this implementation is similar to that of FIG. 7; however, a beam splitter 800 is disposed between the auto-collimator 700 and the first lens surface 300 and the major surface 216a. Reflections from those surfaces may still be monitored by the auto-collimator 700 for parallelism. The interface imager 404 may be used to monitor the distance between surfaces. In this example, the interface imager 404 may be an imager such as a microscope or an interferometer.. The interface imager 404 is configured toDocket: SSMP 45896 (Lumus 00202-3US)receive portions of the reflections of the beams from the auto-collimator 700 that have been reflected by the beam splitter 800. When implemented as an interferometer, the interface imager 404 may detect shearing in interference fringes to determine a height difference between the first lens surface 300 and the major surface 216a. No shearing may indicate collinearity. When the two conditions are met (e.g., during relative movement between the optical waveguide 102 and the PBS 206), the interface between the optical waveguide 102 and the PBS 206 may be secured (e.g., the adhesive cured). The misalignment is not shown but would involve non-parallel beams detected by the auto-collimator 700 and / or offset surfaces determined by the interface imager 404.

[0075] It should be noted that, when the interface imager 404 is implemented as an interferometer, the interface imager 404 may be used to determine the parallelism and offset between the major surface 216a and the first lens surface 300. For example, shearing may represent the offset and a tilt of an interference pattern may represent the non-parallelism.However, in many case, determining the non-parallelism may take more time. Accordingly, the auto-collimator 700 may reduce an overall time of the alignment.

[0076] This apparatus / implementation also allows for a flexible manufacturing path. For example, only the PBS 206 and the optical waveguide 102 are needed to perform the alignment. Other components that may ultimately be coupled with the PBS 206 (e.g., the lenses, the projector 106, etc.) may be attached prior to or after the alignment, or some combination thereof.

[0077] FIG. 9A illustrates another example of a misalignment between the optical waveguide 102 and the PBS 206 from the optical assembly 200. The major surface 216a is non-parallel to the first lens surface 300, and the major surface 216a is offset from the first lens surface 300. The apparatus in this implementation uses the auto-collimator 700; however, a slab 900 (e.g., mirror) is placed over the interface between the optical waveguide 102 and the PBS 206 such that it is in contact with the first lens surface 300 and the major surface 216a. The autocollimator 700 projects light onto the first lens surface 300, the slab 900, and the major surface 216a and receives reflections of the light therefrom.Docket: SSMP 45896 (Lumus 00202-3US)

[0078] FIG. 9B illustrates an example of an output from the auto-collimator 700 for the case of FIG. 9A. The auto-collimator 700 may produce reflected markers 902 (e.g., reflected markers 902a, 902b, and 902c). Because of the translation and angular displacement of the interface, the reflected markers 902 are dispersed from one another.

[0079] FIG. 10A illustrates the misalignment between the optical waveguide 102 and the PBS 206 from the optical assembly 200 of FIG. 9A having been partially corrected (or another misalignment). The major surface 216a is parallel to the first lens surface 300; however, the major surface 216a is offset from the first lens surface 300.

[0080] FIG. 10B illustrates an example of an output from the auto-collimator 700 for the case of FIG. 10A. Because the major surface 216a is parallel to the first lens surface 300, two of the reflected markers 902 (e.g., reflected markers 902a and 902b) may be close together. Because the translation of the interface still exists, a third of the reflected markers 902 (e.g. reflected marker 902c) is away from the two other reflected markers 902.

[0081] FIG. 11A illustrates an alignment between the optical waveguide 102 and the PBS 206 from the optical assembly 200. The major surface 216a is parallel to the first lens surface 300, and the major surface 216a is not or very minorly offset from the first lens surface 300.

[0082] FIG. 1 IB illustrates an example of an output from the auto-collimator 700 for the case of FIG. 11A. Because the major surface 216a is parallel to the first lens surface 300 and not far offset therefrom, the three reflected markers 902 (e.g., reflected markers 902a, 902b, and 902c) may be close together. Furthermore, if the slab 900 is distorted (top and bottom surfaces not parallel) then an offset may be derived and the alignment may be relative to the offset.

[0083] FIG. 12A illustrates an example of a misalignment between the second reflective lens 214 and the PBS 206 of the optical assembly 200. The PBS 206 is coupled with the optical waveguide 102 and aligned therewith. The misalignment may be due to a translation of the second reflective lens 214 relative to the second lens surface 302.

[0084] To measure the misalignment, an apparatus may comprise a light source and the light imager 402. It should be noted that the apparatus may be the same as that used for FIGS. 4A andDocket: SSMP 45896 (Lumus 00202-3US)4B. Thus, the light beam 202 is shown (may be produced by projector 106 or another light source). The light beam 202 is split by the splitting component 208; however, due to the second reflecting lens 214 being disposed on the second lens surface 302, both components of the light beam 202 exit the PBS 206. A first portion of the light beam 202 passes through the splitting component 208, is reflected by the first reflecting lens 210, is reflected by the splitting component 208, exits the PBS 206, enters the optical waveguide 102, and is coupled out via the coupling-out region 218. A second portion of the light beam 202 is reflected by the splitting component 208, is reflected by the second reflecting lens 214, passes through the splitting component 208, exits the PBS 206, enters the optical waveguide 102, and is coupled out via the coupling-out region 218.

[0085] The light imager 402 is again used to receive the portions of the light beam 202 that exit the optical waveguide 102 via the coupling-out region 218. Because of the misalignment between the second reflecting lens 214 and the PBS 206, the two beams are not parallel. The light imager 402 may be configured to detect the non-parallelism to determine an amount of the misalignment.

[0086] FIG. 12B illustrates an example of an alignment between the second reflecting lens 214 and the PBS 206 of the optical assembly 200. The alignment may involve a correction from the example of FIG. 12A. To do so, a movement system of the apparatus (not shown) may manipulate the second reflecting lens 214 and / or the PBS 206 / optical waveguide 102 assembly.

[0087] Using the same setup as FIG. 12A, the light imager 402 may be used to determine when the beams are parallel. When the beams are parallel, the adhesive disposed between the second reflecting lens 214 and the PBS 206 may be cured. For example, if the adhesive is an ultraviolet (UV) cure adhesive, a UV light of the apparatus may be used to cure the adhesive. If the adhesive is a non-UV cure adhesive, the second reflecting lens 214 may be held in place until it cures.Example Major-Surface Input Optical AssemblyDocket: SSMP 45896 (Lumus 00202-3US)

[0088] FIG. 13 illustrates an example of an optical assembly 1300 including the projector 106, the PBS assembly 112, and the optical waveguide 102. The optical assembly 1300 is similar to the optical assembly 200, thus, the same numbered components will be used. The projector 106 is configured to produce the light beams 202. Only one light beam 202 is shown for simplicity. The light beam 202 may pass through the field lens 204 before entering the PBS 206.

[0089] The PBS 206 includes the splitting component 208 configured to split the light beam 202 into two polarized beams (shown as dashed and dot / dashed lines). A first of the polarized beams continues in a same direction as the light beam 202 to the first reflecting lens 210, is reflected by the first reflecting lens 210 back to the splitting component 208, and is reflected by the splitting component 208 to exit the PBS 206 and enter the optical waveguide 102. A second of the polarized beams is reflected by the splitting component 208 to the second reflecting lens 214, is reflected by the second reflecting lens 214 back through the splitting component 208 to exit the PBS 206 and enter the optical waveguide 102. For the purposes of this disclosure, the PBS 206 may be a include the field lens 204 or may be a separate component. Along similar lines, the PBS assembly 112 may include the PBS 206, the first reflecting lens 210, and the second reflecting lens 214. Groupings of the components may change without departing from the scope of this disclosure.

[0090] A first waveplate (e.g., X / 4 waveplate) may be disposed between the first reflecting lens 210 and the PBS 206 to ensure that returning polarization is orthogonal such that the beam can enter the optical waveguide 102. Similarly, a second waveplate (e.g., X / 4 waveplate) may be disposed between the second reflecting lens 214 and the PBS 206 to ensure that returning polarization is orthogonal such that the beam can enter the optical waveguide 102. The waveplates are not shown for clarity.

[0091] Once the light beam 202 (e.g., polarized portions thereof) has exited the PBS 206, it enters the optical waveguide 102 (shown as a single beam for clarity). The optical waveguide 102 includes a coupling-in mirror 1302 configured to receive the light beam 202 and reflect the light beam 202 towards one of the major surfaces 216 (e.g., major surface 216a or major surfaceDocket: SSMP 45896 (Lumus 00202-3US)216b) that are flat and parallel to one another. The light beam 202 reflects between the major surfaces 216 due to total-internal-reflection (TIR).

[0092] The optical waveguide 102 includes the coupling-out region 218 including a plurality of facets. The facets are parallel to one another and formed of respective partially reflective optical elements or surfaces. An end facet (e.g., the far left in the illustrated example) may be fully reflective. As the light beam 202 propagates through the optical waveguide 102 via TIR, it hits each facet. Each facet partially reflects the light beam 202 such that it exits the optical waveguide 102 via one of the major surfaces 216 (e.g., to a user’s eye).

[0093] Only the facets of the coupling-out region 218 are shown. There may be another set of facets between the coupling-out region 218 and the PBS 206. For example, the other set of facets may expand the light beam 202 in a first dimension, while the facets of the coupling-out region may expand the light beam 202 in a second dimension. The configuration of the facets within the optical waveguide 102 may vary without departing from the scope of this disclosure.

[0094] FIG. 14 illustrates example alignments of the optical assembly 1300 to produce quality images. The projector 106 has been removed as it may not be necessary for some of the alignment procedures; however, it may be attached without departing from the scope of this disclosure.

[0095] The PBS 206 includes the first lens surface 300, the second lens surface 302, and the output aperture surface 304. The first lens surface 300 is proximate the first reflecting lens 210, and the second lens surface 302 is proximate the second reflecting lens 214. Depending on configuration, an alignment block may be attached between the first reflecting lens 210 and the first lens surface 300, or between the second reflecting lens 214 and the second lens surface 302. The output aperture surface 304 is a surface through which light beams exit the PBS 206. Once they have exited, the light beams enter the optical waveguide 102 via one of the major surfaces 216 (e.g., the major surface 216b in the illustrated example).

[0096] In the optical assembly 1300, two alignments may be required to achieve good optical performance. The first alignment is between the PBS 206 and the optical waveguide 102. ForDocket: SSMP 45896 (Lumus 00202-3US)the first alignment, the first lens surface 300 should be aligned with the coupling-in mirror 1302. Furthermore, an intersection of the coupling-in mirror 1302 with the major surface 216b of the optical waveguide 102 should be at a same level or slightly above the first lens surface 300 (e.g., left in the illustrated example).

[0097] The second alignment is between the PBS 206 and the second reflecting lens 214. For the second alignment, the second reflecting lens 214 may be translated along the second lens surface 302. The second alignment may be performed after the first alignment. That is, the optical waveguide 102 may be aligned / attached to the PBS 206 when the second alignment occurs. Depending upon implementation, the field lens 204 and / or the projector 106 may be coupled to the PBS 206 for the second alignment. In an alternate implementation, the second reflecting lens 214 may be attached to the PBS 206 prior to the second alignment, and the second alignment may involve aligning the first reflecting lens 210 relative to the first lens surface 300.

[0098] The two alignments may be performed while adhesives disposed between the respective interfaces are un-cured. The adhesive may allow for light beams to propagate therethrough while also allowing for, as long as the adhesive is not cured, relative movement between the optical waveguide 102 and the PBS 206 and / or between the PBS 206 and the second reflecting lens 214. For example, an adhesive may be disposed between the PBS 206 and the optical waveguide 102 and cured after the first alignment. Similarly, the adhesive (or another adhesive) may be disposed between the PBS 206 and the second reflecting lens 214 and cured after the second alignment. The adhesive may, for example, be a UV-cure adhesive, and curing may involve applying a UV-light to the adhesive. The adhesive may allow for the light beam 202 to propagate therethrough while also allowing for, as long as the adhesive is not cured, relative movement between the optical waveguide 102 and the PBS 206.

[0099] FIG. 15 illustrates an example of an alignment between the optical waveguide 102 and the PBS 206 of the optical assembly 1300. A light source (not shown) produces the light beam 202 that is split by the splitting component 208 (only the portion that passes through the splitting component 208 is shown as the other portion exits the PBS 206). The portion of the light beam 202 is reflected by the first reflecting lens 210, is reflected by the splitting component 208, exitsDocket: SSMP 45896 (Lumus 00202-3US)the PBS 206, enters the optical waveguide 102, and is coupled out via the coupling-out region 218. The light beam 202 may be produced by the projector 106 if it is attached, or it may be produced by a different source. The light beam 202 has a width that is represented by the two dashed lines. A portion of the light beam 202 is reflected by the first lens surface 300 prior to exiting the PBS 206. Because the coupling-in mirror 1302 reflects the beams as they enter the optical waveguide 102, the requirements for parallelism and co-planarity (described herein), are derived for a virtual image generated by folding the beams around the coupling-in mirror 1302. To illustrate, the relative portions of the light beam 202 are shown as two beams. One of the beams is reflected directly from the splitting component 208 to exit the PBS 206, while another of the beams is reflected off the first lens surface 300 prior to exiting the PBS 206. Because the virtual image of the first lens surface 300 (shown as the plane itself) is not parallel with the major surface 216a, the beams are not parallel. Furthermore, if the first lens surface 300 is not coplanar with the major surface 216a, the beams are not coherently constructive.

[0100] The light imager 402 is again configured to receive the light beam 202 as it exits the optical waveguide 102 via the coupling-out region 218. In the illustrated example, only a single facet of the coupling-out region 218 is shown. The light imager 402 may be configured to receive the light beam 202 from any number of the facets of the coupling-out region 218. The light imager 402 may be configured to detect the parallelism to determine an amount of the angular misalignment.

[0101] The interface imager 404 is configured to monitor a height difference between an intersection of the coupling-in mirror 1302 and the major surface 216b and an intersection of the first lens surface 300 and the output aperture surface 304. To do so, the interface imager 404 may be disposed on a side of the interface (e.g., facing into or out of the page). The interface imager 404 is shown to the side of the interface for clarity.

[0102] The illustrated example shows an alignment between the optical waveguide 102 and the PBS 206 of the optical assembly 1300. The alignment may involve a correction from a previously unaligned interface. To get to the aligned state, a movement system of the apparatus (not shown) may manipulate the optical waveguide 102 and / or the PBS 206. When bothDocket: SSMP 45896 (Lumus 00202-3US)alignment conditions are true (e.g., parallel beams detected by the light imager 402 and the distance detected by the interface imager is within the threshold distance), the adhesive disposed between the optical waveguide 102 and the PBS 206 may be cured. For example, if the adhesive is an ultraviolet (UV) cure adhesive, a UV light of the apparatus may be used to cure the adhesive. If the adhesive is a non-UV cure adhesive, the optical waveguide 102 and the PBS 206 may be held in place until it cures.

[0103] It should be noted that the second reflecting lens 214 may be coupled with the PBS 206 instead of the first reflecting lens 210 for the alignment. In other words, either of the reflecting lenses may be attached to the PBS 206 to perform the alignment between the PBS 206 and the optical waveguide 102..

[0104] FIG. 16 illustrates another example of an alignment between the optical waveguide 102 and the PBS 206 from the optical assembly 1300. The apparatus is similar to that of FIG. 15, except that the collimated light beam 500 (e.g., produced by the collimated light source 502) is injected into the PBS 206 via the second lens surface 302. A portion of the collimated light beam 500 is reflected by the first lens surface 300 prior to exiting the PBS 206 while another portion of the collimated light beam 500 exits the PBS 206 directly.

[0105] The alignment process is similar to that of FIG. 15. That is, the light imager 402 may be used to determine when the beams are parallel. The interface imager 404 may be used to determine when the points are close to each other. When the two conditions are met (e.g., during relative movement between the optical waveguide 102 and the PBS 206), the interface between the optical waveguide 102 and the PBS 206 may be secured (e.g., the adhesive cured). The misalignment is not shown but would involve non-parallel beams and / or offset intersection points.

[0106] In some implementations, the collimated light beam 500 may be injected through the first lens surface 300. Similar results may be achieved by switching which direction the collimated light beam 500 enters the PBS 206. Furthermore, more or less components may be attached to the PBS 206 for this implementation. As an example, the field lens may not be present for the alignment. Furthermore, the projector 106 and / or one of the reflecting lensesDocket: SSMP 45896 (Lumus 00202-3US)(e.g., the first reflecting lens 210) may be attached to the PBS 206 without departing from the scope of this disclosure.

[0107] FIG. 17 illustrates the example of FIG. 16 with the shutters 600 configured to block respective portions of the collimated light beam 500. For example, because it may be difficult for the light imager 402 (or a user) to determine parallelism between the beams, portions of the collimated light beam 500 may be blocked sequentially to produce two images. The two images may be used to better and / or more easily determine parallelism between the beams.

[0108] FIG. 18 illustrates an example of an alignment between the second reflective lens 214 and the PBS 206 of the optical assembly 1300. The PBS 206 is coupled with the optical waveguide 102 and aligned therewith. To measure the alignment, an apparatus may comprise a light source and the light imager 402. It should be noted that the apparatus may be the same as that used for FIG. 15. Thus, the light beam 202 is shown (may be produced by projector 106 or another light source). The light beam 202 is split by the splitting component 208; however, due to the second reflecting lens 214 being disposed on the second lens surface 302, both components of the light beam 202 exit the PBS 206. A first portion of the light beam 202 passes through the splitting component 208, is reflected by the first reflecting lens 210, is reflected by the splitting component 208, exits the PBS 206, enters the optical waveguide 102, and is coupled out via the coupling-out region 218. A second portion of the light beam 202 is reflected by the splitting component 208, is reflected by the second reflecting lens 214, passes through the splitting component 208, exits the PBS 206, enters the optical waveguide 102, and is coupled out via the coupling-out region 218.

[0109] The light imager 402 is again used to receive the portions of the light beam 202 that exit the optical waveguide 102 via the coupling-out region 218. Because of the alignment between the second reflecting lens 214 and the PBS 206, the two beams are parallel. The light imager 402 may be configured to detect parallelism to determine an amount of misalignment.

[0110] The alignment may involve a correction from a previously unaligned interface. To get to the aligned state, a movement system of the apparatus (not shown) may manipulate the second reflecting lens 214 and / or the PBS 206. When the light imager 402 determines that theDocket: SSMP 45896 (Lumus 00202-3US)beams are parallel, the adhesive disposed between the second reflecting lens 214 and the PBS 206 may be cured. For example, if the adhesive is an ultraviolet (UV) cure adhesive, a UV light of the apparatus may be used to cure the adhesive. If the adhesive is a non-UV cure adhesive, the second reflecting lens 214 and the PBS 206 may be held in place until it cures.Example Methods

[0111] FIG. 19 illustrates an example of a method 1900 of aligning an optical waveguide with a PBS in accordance with this disclosure. The method 1900 may be applicable to the optical assembly 200.

[0112] At 1902, an optical waveguide is oriented relative to a PBS such that an intersection of a major surface and an end surface of the optical waveguide is proximate an intersection of a lens surface and an output aperture surface of the PBS. For example, the optical waveguide 102 may be oriented relative to the PBS 206 such that the intersection of the major surface 216a and the end surface 306 of the optical waveguide 102 are proximate the intersection of the first lens surface 300 and the output aperture surface 304 of the PBS 206.

[0113] At 1904, a light beam is projected into the PBS such that it exits the PBS via the output aperture surface of the PBS, enters the optical waveguide via the end surface of the optical waveguide, and exits the optical waveguide via a plurality of partially reflecting facets. For example, the light beam 202 may be projected into the PBS 206 such that it exits the PBS 206 via the output aperture surface 304, enters the optical waveguide 102 via the end surface 306 of the optical waveguide 102, and exits the optical waveguide 102 via the coupling-out region 218. As another example, the collimated light beam 500 may be projected into the PBS 206 such that it exits the PBS 206 via the output aperture surface 304, enters the optical waveguide 102 via the end surface 306 of the optical waveguide 102, and exits the optical waveguide 102 via the coupling-out region 218.

[0114] At 1906, parallelism is monitored, via a light imager, between first and second portions of the light beam that have exited the optical waveguide. For example, the light imager 402 may monitor parallelism between portions of the light beam 202. As another example, theDocket: SSMP 45896 (Lumus 00202-3US)light imager 402 may monitor parallelism between portions of the collimated light beam 500.

[0115] At 1908, the optical waveguide is moved relative to the PBS. For example, the optical waveguide 102 may be moved relative to the PBS 206 (e.g., by a movement system).

[0116] At 1910, responsive to determining, via the light imager, that the first and second portions of the light beam that have exited the optical waveguide are parallel, the optical waveguide is secured to the PBS. For example, responsive to determining, via the light imager 402, that the portions of the light beam 202 that have exited the optical waveguide are parallel, securing the optical waveguide 102 to the PBS 206. As another example, responsive to determining, via the light imager 402, that the portions of the collimated light beam 500 that have exited the optical waveguide are parallel, securing the optical waveguide 102 to the PBS 206. The securing may involve curing an adhesive.

[0117] FIG. 20 illustrates an example of a method 2000 of aligning an optical waveguide with a PBS in accordance with this disclosure. The method 2000 may be applicable to the optical assembly 1300.

[0118] At 2002, an optical waveguide is oriented relative to a PBS such that an intersection of a major surface and a coupling-in mirror of the optical waveguide is proximate an intersection of a lens surface and an output aperture surface of the PBS. For example, the optical waveguide 102 may be oriented relative to the PBS 206 such that the intersection of the major surface 216b and the coupling-in mirror 1302 of the optical waveguide 102 is proximate the intersection of the first lens surface 300 and the output aperture surface 304of the PBS 206.

[0119] At 2004, a light beam is projected into the PBS such that it exits the output aperture surface of the PBS, enters the major surface of the optical waveguide, reflects off the coupling-in mirror, and exits the optical waveguide via a plurality of partially reflecting facets. For example, the light beam 202 may be projected into the PBS 206 such that it exits the PBS 206 via the output aperture surface 304, enters the optical waveguide 102 via the major surface 216b of the optical waveguide 102, reflects off the coupling-in mirror 1302, and exits the optical waveguide 102 via the coupling-out region 218. As another example, the collimated light beamDocket: SSMP 45896 (Lumus 00202-3US)500 may be projected into the PBS 206 such that it exits the PBS 206 via the output aperture surface 304, enters the optical waveguide 102 via the end surface 306 of the optical waveguide 102, and exits the optical waveguide 102 via the coupling-out region 218.

[0120] At 2006, parallelism is monitored, via a light imager, between first and second portions of the light beam that have exited the optical waveguide. For example, the light imager 402 may monitor parallelism between portions of the light beam 202. As another example, the light imager 402 may monitor parallelism between portions of the collimated light beam 500.

[0121] At 2008, the optical waveguide is moved relative to the PBS. For example, the optical waveguide 102 may be moved relative to the PBS 206 (e.g., by a movement system).

[0122] At 2010, responsive to determining, via the light imager, that the first and second portions of the light beam that have exited the optical waveguide are parallel, the optical waveguide is secured to the PBS. For example, responsive to determining, via the light imager 402, that the portions of the light beam 202 that have exited the optical waveguide are parallel, securing the optical waveguide 102 to the PBS 206. As another example, responsive to determining, via the light imager 402, that the portions of the collimated light beam 500 that have exited the optical waveguide are parallel, securing the optical waveguide 102 to the PBS 206. The securing may involve curing an adhesive.

[0123] FIG. 21 illustrates an example of a method 2100 of aligning an optical waveguide with a PBS in accordance with this disclosure. The method 2100 may be applicable to the optical assembly 200.

[0124] At 2102, an optical waveguide is oriented relative to a PBS such that an intersection of a major surface and an end surface of the optical waveguide is proximate an intersection of a lens surface and an output aperture surface of the PBS. For example, the optical waveguide 102 may be oriented relative to the PBS 206 such that the intersection of the major surface 216a and the end surface 306 of the optical waveguide 102 are proximate the intersection of the first lens surface 300 and the output aperture surface 304 of the PBS 206.Docket: SSMP 45896 (Lumus 00202-3US)

[0125] At 2104, first and second portions of a light beam are projected, via an autocollimator, onto the major surface and the lens surface, respectively. For example, the autocollimator 700 may project light onto the major surface 216a and the first lens surface 300.

[0126] At 2106, parallelism is monitored, via the auto-collimator, between reflections of the first and second portions of the light beam. For example, the auto-collimator 700 may receive reflections of the first and second portions of the light beam that were reflected by the major surface 216a and the first lens surface 300, respectively, and monitor parallelism between the reflections of the first and second portions of the light beam.

[0127] At 2108, the optical waveguide is moved relative to the PBS. For example, the optical waveguide 102 may be moved relative to the PBS 206 (e.g., by a movement system).

[0128] At 2110, responsive to determining, via the auto-collimator, that the reflections of the first and second portions of the light beam are parallel, the optical waveguide is secured to the PBS. For example, responsive to determining, via the auto-collimator 700, that the reflections of the light projected onto the major surface 216a and the first lens surface 300 are parallel, securing the optical waveguide 102 to the PBS 206. The securing may involve curing an adhesive.

[0129] FIG. 22 illustrates an example of a method 2200 of aligning an optical waveguide with a PBS in accordance with this disclosure. The method 2200 may be applicable to the optical assembly 200.

[0130] At 2202, an optical waveguide is oriented relative to a PBS such that an intersection of a major surface and an end surface of the optical waveguide is proximate an intersection of a first lens surface and an output aperture surface of the PBS. For example, the optical waveguide 102 may be oriented relative to the PBS 206 such that the intersection of the major surface 216a and the end surface 306 of the optical waveguide 102 are proximate the intersection of the first lens surface 300 and the output aperture surface 304 of the PBS 206.

[0131] At 2204, a slab is placed proximate an interface between the optical waveguideDocket: SSMP 45896 (Lumus 00202-3US)and the PBS such that the slab is in contact with the major surface of the optical waveguide and the lens surface of the PBS. For example, the slab 900 may be placed proximate the interface between the optical waveguide 102 and the PBS 206 such that the slab 900 is in contact with the major surface 216a of the optical waveguide 102 and the first lens surface 300 of the PBS 206.

[0132] At 2206, first, second, and third portions of a light beam are projected, via an auto-collimator, onto the major surface, the slab, and the lens surface, respectively. For example, the auto-collimator 700 may project light onto the major surface 216a, the slab 900, and the first lens surface 300.

[0133] At 2208, parallelism is monitored, via the auto-collimator, between reflections of the first, second, and third portions of the light beam. For example, the auto-collimator 700 may receive reflections of the first, second, and third portions of the light beam that were reflected by the major surface 216a, the slab 900, and the first lens surface 300, respectively, and monitor parallelism between the reflections of the first, second, and third portions of the light beam.

[0134] At 2210, the optical waveguide is moved relative to the PBS. For example, the optical waveguide 102 may be moved relative to the PBS 206 (e.g., by a movement system).

[0135] At 2212, responsive to determining, via the auto-collimator, that the reflections of the first, second, and third portions of the light beam are parallel, the optical waveguide is secured to the PBS. For example, responsive to determining, via the auto-collimator 700, that the reflections of the light projected onto the major surface 216a, the slab 900, and the first lens surface 300 are parallel, securing the optical waveguide 102 to the PBS 206. The securing may involve curing an adhesive.

[0136] FIG. 23 illustrates an example of a method 2300 of aligning a second reflective lens to a PBS in accordance with this disclosure. The method 2300 may be applicable to the optical assembly 200 or the optical assembly 1300.

[0137] At 2302, a second reflective lens is oriented proximate a second lens surface of an assembly of a PBS, an optical waveguide coupled with an output aperture surface of the PBS,Docket: SSMP 45896 (Lumus 00202-3US)and a first reflective lens coupled with a first lens surface of the PBS. For example, the second reflective lens 214 may be oriented proximate the second lens surface 302 of an assembly of the PBS 206, the optical waveguide 102, and the first reflective lens 210. An intersection between the optical waveguide 102 and the PBS 206 may have been previously aligned.

[0138] At 2304, a light beam is projected into the PBS such that a first portion of the light beam passes through a splitting component of the PBS, is reflected off the first reflecting lens, and is reflected off the splitting component to exit the PBS via the output aperture surface of the PBS, and a second portion of the light beam is reflected by the splitting component, is reflected by the second reflecting lens, and passes through the splitting component to exit the PBS via the output aperture surface of the PBS, wherein the first and second portions of the light beam enter the optical waveguide and exit the optical waveguide via the plurality of partially reflecting facets. For example, the light beam 202 may be projected into the PBS 206 such that a first portion of the light beam 202 passes through the splitting component 208, is reflected off the first reflecting lens 210, and is reflected off the splitting component 208 to exit the PBS 206 via the output aperture surface 304, and a second portion of the light beam 202 is reflected by the splitting component 208, is reflected by the second reflecting lens 214, and passes through the splitting component 208 to exit the PBS 206 via the output aperture surface 304. The first and second portions of the light beam 202 may enter the optical waveguide 102 (e.g., via the end surface 306 or the major surface 216b) and exit the optical waveguide 102 via the coupling-out region 218.

[0139] At 2306, parallelism is monitored, via a light imager, between first and second portions of the light beam that have exited the optical waveguide. For example, the light imager 402 may monitor parallelism between the first and second portions of the light beam 202 discussed above in regard to step 2304 after they have exited the optical waveguide 102.

[0140] At 2308, the second reflecting lens is translated relative to the PBS. For example, the second reflecting lens 214 may be translated along the second lens surface 302 (e.g., by a movement system).Docket: SSMP 45896 (Lumus 00202-3US)

[0141] At 2310, responsive to determining, via the light imager, that the first and second portions of the light beam that have exited the optical waveguide are parallel, the second reflecting lens is secured to the PBS. For example, responsive to determining, via the light imager 402, that the portions of the light beam 202 that have exited the optical waveguide 102 are parallel, securing the second reflecting lens 214 to the PBS 206.Example Alignment Apparatus

[0142] FIG. 24 illustrates an example of an apparatus 2400 usable to perform any of the alignments discussed above. The components are all optional; however, it may be assumed that at least one of them is implemented within the apparatus 2400 for each implementation. It should be clear which components are used for which of the alignments above (and optional ones for each based on their descriptions).

[0143] The apparatus 2400 may include a movement system 2402. The movement system 2402 may be configured to move components of the optical assembly 200 or the optical assembly 1300 relative to each other. For example, the movement system 2402 may be configured to move the optical waveguide 102 relative to the PBS 206 and / or move the second reflective lens 214 relative to the PBS 206. The movement system 2402 may be any mechanical or electromechanical system configured to perform the necessary movements of the components.

[0144] The apparatus 2400 may also include a lighting system 2404. For example, the lighting system 2404 may include a light source to produce light beam 202. The lighting system 2404 may also include the collimated light source 502 to produce the collimated light beam 500.

[0145] The apparatus 2400 may also include the light imager 402. The light imager 402 may be an imager (e.g., camera or microscope) configured to monitor parallelism between portions of received light or lack thereof (e.g., blurry portions).

[0146] The apparatus 2400 may also include the interface imager 404. The interface imager 404 may be an imager (e.g., camera, microscope, or interferometer) capable of determining distances between the surfaces (e.g., in optical assembly 200) or between the intersection points (e.g., in optical assembly 1300). When implemented as an interferometer, theDocket: SSMP 45896 (Lumus 00202-3US)interface imager 404 may be configured to detect shearing in interference fringes to determine height differences between the respective surfaces.

[0147] The apparatus 2400 may also include the auto-collimator 700. The autocollimator 700 may be configured to produce a collimated light beam and determine parallelism between reflected portions of the collimated light beam.

[0148] The apparatus 2400 may also include a cure system 2406. The cure system 2406 may include a heat source or a light (e.g., UV-light) configured to cure an adhesive used for the interfaces discussed above.

[0149] The apparatus 2400 may also include a processing system 2408. The processing system 2408 may include at least one processor and memory comprising instructions that, when executed by the processor, cause the processor to implement the methods (or portions thereof) discussed above. For example, the processing system 2408 may control the movement system 2402 to move optical components of the optical assembly 200 or the optical assembly 1300 until other components of the apparatus 2400 (e.g., the light imager 402, the interface imager 404, and / or the auto-collimator 700) indicate that the optical components are aligned. Responsive to determining that the components are aligned, the processing system 2408 may control the cure system 2406 to cure an adhesive between the optical components.Examples

[0150] Example 1 : A method comprising: orienting an optical waveguide relative to a polarizing beam-splitter (PBS) such that an intersection of a major surface and an end surface of the optical waveguide is proximate an intersection of a first lens surface and an output aperture surface of the PBS; projecting a light beam into the PBS such that it exits the output aperture surface of the PBS, enters the end surface of the optical waveguide, and exits the optical waveguide via a plurality of partially reflecting facets; monitoring, via a light imager, parallelism between first and second portions of the light beam that have exited the optical waveguide; moving the optical waveguide relative to the PBS; and responsive to determining, via the lightDocket: SSMP 45896 (Lumus 00202-3US)imager, that the first and second portions of the light beam that have exited the optical waveguide are parallel, securing the optical waveguide to the PBS.

[0151] Example 2: The method of example 1, wherein: the method further comprises monitoring, via an interface imager, a distance between the major surface of the optical waveguide and the first lens surface of the PBS; and the securing the optical waveguide to the PBS is further responsive to determining, via the interface imager, that the major surface of the optical waveguide is at a same level or within a threshold distance of the first lens surface of the PBS.

[0152] Example 3: The method of example 1 or 2, wherein: the projecting the light beam into the PBS comprises projecting the light beam into the PBS such that a portion of the light beam passes through a splitting component of the PBS, is reflected off a first reflecting lens that is coupled with the PBS, and is reflected off the splitting component to exit the PBS via the output aperture surface of the PBS; and the first and second portions of the light beam that have exited the optical waveguide correspond to respective portions of the portion of the light beam that passed through the splitting component.

[0153] Example 4: The method of example 3, wherein the first portion of the light beam reflects off the first lens surface of the PBS prior to exiting the PBS.

[0154] Example 5: The method of example 3 or 4, further comprising: orienting a second reflecting lens proximate a second lens surface of the PBS; projecting another light beam into the PBS such that a first portion of the other light beam passes through the splitting component of the PBS, is reflected off the first reflecting lens, and is reflected off the splitting component to exit the output aperture surface of the PBS and a second portion of the other light beam is reflected by the splitting component, is reflected by the second reflecting lens, and passes through the splitting component to exit the output aperture surface of the PBS, wherein the first and second portions of the other light beam enter the end surface of the optical waveguide, and exit the optical waveguide via the plurality of partially reflecting facets; monitoring, via the light imager, parallelism between the first and second portions of the other light beam that have exited the optical waveguide; translating the second reflecting lens relative to the PBS; and securing the second reflecting lens to the PBS responsive to determining, via the light imager, that the first and second portions of the other light beam that have exited the optical waveguide are parallel.Docket: SSMP 45896 (Lumus 00202-3US)

[0155] Example 6: The method of example 5, wherein the first portion of the light beam reflects off the first lens surface of the PBS prior to exiting the PBS.

[0156] Example 7: The method of any previous example, wherein: the projecting the light beam into the PBS comprises projecting a collimated light beam into the PBS such that a first portion of the collimated light beam exits the output aperture surface of the PBS directly and another portion of the collimated light beam reflects off the first lens surface prior to exiting the output aperture surface; and the first and second portions of the light beam that have exited the optical waveguide correspond to the first and second portions of the collimated light beam.

[0157] Example 8: The method of example 7, wherein: the method further comprises: blocking the first portion of the collimated light beam prior to the first portion of the collimated light beam entering the PBS; imaging, via the light imager, the second portion of the collimated light beam that has exited the optical waveguide; blocking the second portion of the collimated light beam prior to the second portion of the collimated light beam entering the PBS; and imaging, via the light imager, the first portion of the collimated light beam that has exited the optical waveguide; and monitoring parallelism between the first and second portions of the collimated light beam that have exited the optical waveguide is based on the imaged first and second portions of the collimated light beam that have exited the optical waveguide.

[0158] Example 9: The method of any previous example, wherein the securing the optical waveguide to the PBS comprises curing an adhesive disposed between the optical waveguide and the PBS.

[0159] Example 10: The method of example 9, wherein: the adhesive comprises an ultraviolet (UV)-cure adhesive; and the curing the adhesive comprises applying a UV light to the adhesive.

[0160] Example 11 : An apparatus comprising: a movement system configured to position an optical waveguide relative to a polarizing beam-splitter (PBS) such that an intersection of a major surface and an end surface of the optical waveguide is proximate an intersection of a first lens surface and an output aperture surface of the PBS; a lighting system configured to project a light beam into the PBS such that it exits the output aperture surface of the PBS, enters the end surface of the optical waveguide, and exits the optical waveguide via a plurality of partially reflecting facets; a light imager configured to monitor parallelism between first and secondDocket: SSMP 45896 (Lumus 00202-3US)portions of the light beam that have exited the optical waveguide; a cure system configured to secure the optical waveguide to the PBS; and a processing system configured to: cause the movement system to move the optical waveguide relative to the PBS; and responsive to determining, via the light imager, that the first and second portions of the light beam that have exited the optical waveguide are parallel, cause the cure system to secure the optical waveguide to the PBS.

[0161] Example 12: The apparatus of example 11, wherein: the apparatus further comprises an interface imager configured to monitor a distance between the major surface of the optical waveguide and the first lens surface of the PBS; and the processing system is further configured to secure the optical waveguide to the PBS responsive to determining, via the interface imager, that the major surface of the optical waveguide is at a same level or within a threshold distance of the first lens surface of the PBS.

[0162] Example 13: The apparatus of example 11 or 12, wherein: the lighting system is further configured to project the light beam into the PBS such that a portion of the light beam passes through a splitting component of the PBS, is reflected off a first reflecting lens that is coupled with the PBS, and is reflected off the splitting component to exit the PBS via the output aperture surface of the PBS; and the first and second portions of the light beam that have exited the optical waveguide correspond to respective portions of the portion of the light beam that passed through the splitting component.

[0163] Example 14: The apparatus of example 13, wherein the lighting system is further configured to project the light beam into the PBS such that the first portion of the light beam reflects off the first lens surface of the PBS prior to exiting the PBS.

[0164] Example 15: The apparatus of example 13 or 14, wherein: the movement system is further configured to orient a second reflecting lens proximate a second lens surface of the PBS; the lighting system is further configured to project another light beam into the PBS such that a first portion of the other light beam passes through the splitting component of the PBS, is reflected off the first reflecting lens, and is reflected off the splitting component to exit the output aperture surface of the PBS and a second portion of the other light beam is reflected by the splitting component, is reflected by the second reflecting lens, and passes through the splitting component to exit the output aperture surface of the PBS, wherein the first and second portionsDocket: SSMP 45896 (Lumus 00202-3US)of the other light beam enter the end surface of the optical waveguide, and exit the optical waveguide via the plurality of partially reflecting facets; the light imager is further configured to monitor parallelism between the first and second portions of the other light beam that have exited the optical waveguide; and the processing system is further configured to: cause the movement system to translate the second reflecting lens relative to the PBS; and responsive to determining, via the light imager, that the first and second portions of the other light beam that have exited the optical waveguide are parallel, cause the cure system to secure the second reflecting lens to the PBS.

[0165] Example 16: The apparatus of example 15, wherein the lighting system is further configured to project the light beam into the PBS such the first portion of the light beam reflects off the first lens surface of the PBS prior to exiting the PBS.

[0166] Example 17: The apparatus of any of examples 11-16, wherein: the lighting system is further configured to project the light beam into the PBS as a collimated light beam such that a first portion of the collimated light beam exits the output aperture surface of the PBS directly and another portion of the collimated light beam reflects off the first lens surface prior to exiting the output aperture surface; and the first and second portions of the light beam that have exited the optical waveguide correspond to the first and second portions of the collimated light beam.

[0167] Example 18: The apparatus of example 17, wherein: the apparatus further comprises one or more shutters; and the processing system is further configured to: cause the one or more shutters to block the first portion of the collimated light beam prior to the first portion of the collimated light beam entering the PBS; image, via the light imager, the second portion of the collimated light beam that exits the optical waveguide; cause the one or more shutters to block the second portion of the collimated light beam prior to the second portion of the collimated light beam entering the PBS; image, via the light imager, the first portion of the collimated light beam that has exited the optical waveguide; and monitor parallelism between the first and second portions of the collimated light beam that exit the optical waveguide based on the imaged first and second portions of the collimated light beam that exit the optical waveguide.Docket: SSMP 45896 (Lumus 00202-3US)

[0168] Example 19: The apparatus of any of examples 11-18, wherein causing the cure system to secure the optical waveguide to the PBS comprises causing a curing of an adhesive disposed between the optical waveguide and the PBS.

[0169] Example 20: The apparatus of example 19, wherein: the adhesive comprises an ultraviolet (UV)-cure adhesive; and the causing the curing of the adhesive comprises causing a UV light to be applied to the adhesive.

[0170] Example 21: A method comprising: orienting an optical waveguide relative to a polarizing beam-splitter (PBS) such that an intersection of a major surface and an end surface of the optical waveguide is proximate an intersection of a first lens surface and an output aperture surface of the PBS; projecting a light beam into the PBS such that a portion of the light beam passes through a splitting component of the PBS, is reflected off a first reflecting lens that is coupled with the PBS, is reflected off the splitting component to exit the PBS via an output aperture surface of the PBS, enters the end surface of the optical waveguide, and exits the optical waveguide via a plurality of partially reflecting facets, wherein a first portion of the portion of the light beam that passed through the splitting component reflects off the first lens surface of the PBS prior to exiting the PBS and a second portion of the portion of the light beam that passed through the splitting component does not reflect off the first lens surface of the PBS prior to exiting the PBS; monitoring, via a light imager, parallelism between the first and second portions of the portion of the light beam that passed through the splitting component and exited the optical waveguide; moving the optical waveguide relative to the PBS; and responsive to determining, via the light imager, that the first and second portions of the light beam that have exited the optical waveguide are parallel, securing the optical waveguide to the PBS.Conclusion

[0171] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “includes,” “comprises” and / or “comprising,” when used in this specification, specify the presence of statedDocket: SSMP 45896 (Lumus 00202-3US)features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Further, the terms up, upper, down, lower, above, below, left, right, forward, rearward, and the like are intended to be understood in the context of the representations described and illustrated above so that a wearable device may have such an orientation in reference to the frame or to various elements as supported by the frame or as illustrated in the drawing figures.

[0172] The corresponding structures, materials, acts, and equivalents of all means or step plus function elements, if any, in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The various embodiments were chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

Docket: SSMP 45896 (Lumus 00202-3US)CLAIMSWhat is claimed is:

1. A method comprising:orienting an optical waveguide relative to a polarizing beam-splitter (PBS) such that an intersection of a major surface and an end surface of the optical waveguide is proximate an intersection of a first lens surface and an output aperture surface of the PBS;projecting a light beam into the PBS such that it exits the output aperture surface of the PBS, enters the end surface of the optical waveguide, and exits the optical waveguide via a plurality of partially reflecting facets;monitoring, via a light imager, parallelism between first and second portions of the light beam that have exited the optical waveguide;moving the optical waveguide relative to the PBS; andresponsive to determining, via the light imager, that the first and second portions of the light beam that have exited the optical waveguide are parallel, securing the optical waveguide to the PBS.

2. The method of claim 1, wherein:the method further comprises monitoring, via an interface imager, a distance between the major surface of the optical waveguide and the first lens surface of the PBS; andthe securing the optical waveguide to the PBS is further responsive to determining, via the interface imager, that the major surface of the optical waveguide is at a same level or within a threshold distance of the first lens surface of the PBS.

3. The method of claim 1, wherein:the projecting the light beam into the PBS comprises projecting the light beam into the PBS such that a portion of the light beam passes through a splitting component of the PBS, is reflected off a first reflecting lens that is coupled with the PBS, and is reflected off the splitting component to exit the PBS via the output aperture surface of the PBS; andDocket: SSMP 45896 (Lumus 00202-3US)the first and second portions of the light beam that have exited the optical waveguide correspond to respective portions of the portion of the light beam that passed through the splitting component.

4. The method of claim 3, wherein the first portion of the light beam reflects off the first lens surface of the PBS prior to exiting the PBS.

5. The method of claim 3, further comprising:orienting a second reflecting lens proximate a second lens surface of the PBS; projecting another light beam into the PBS such that a first portion of the other light beam passes through the splitting component of the PBS, is reflected off the first reflecting lens, and is reflected off the splitting component to exit the output aperture surface of the PBS and a second portion of the other light beam is reflected by the splitting component, is reflected by the second reflecting lens, and passes through the splitting component to exit the output aperture surface of the PBS, wherein the first and second portions of the other light beam enter the end surface of the optical waveguide, and exit the optical waveguide via the plurality of partially reflecting facets;monitoring, via the light imager, parallelism between the first and second portions of the other light beam that have exited the optical waveguide;translating the second reflecting lens relative to the PBS; andsecuring the second reflecting lens to the PBS responsive to determining, via the light imager, that the first and second portions of the other light beam that have exited the optical waveguide are parallel.

6. The method of claim 5, wherein the first portion of the light beam reflects off the first lens surface of the PBS prior to exiting the PBS.

7. The method of claim 1, wherein:the projecting the light beam into the PBS comprises projecting a collimated light beam into the PBS such that a first portion of the collimated light beam exits the output apertureDocket: SSMP 45896 (Lumus 00202-3US)surface of the PBS directly and another portion of the collimated light beam reflects off the first lens surface prior to exiting the output aperture surface; andthe first and second portions of the light beam that have exited the optical waveguide correspond to the first and second portions of the collimated light beam.

8. The method of claim 7, wherein:the method further comprises:blocking the first portion of the collimated light beam prior to the first portion of the collimated light beam entering the PBS;imaging, via the light imager, the second portion of the collimated light beam that has exited the optical waveguide;blocking the second portion of the collimated light beam prior to the second portion of the collimated light beam entering the PBS; andimaging, via the light imager, the first portion of the collimated light beam that has exited the optical waveguide; andmonitoring parallelism between the first and second portions of the collimated light beam that have exited the optical waveguide is based on the imaged first and second portions of the collimated light beam that have exited the optical waveguide.

9. The method of claim 1, wherein the securing the optical waveguide to the PBS comprises curing an adhesive disposed between the optical waveguide and the PBS.

10. The method of claim 9, wherein:the adhesive comprises an ultraviolet (UV)-cure adhesive; andthe curing the adhesive comprises applying a UV light to the adhesive.

11. An apparatus comprising:a movement system configured to position an optical waveguide relative to a polarizing beam-splitter (PBS) such that an intersection of a major surface and an end surface of the optical waveguide is proximate an intersection of a first lens surface and an output aperture surface ofDocket: SSMP 45896 (Lumus 00202-3US)the PBS;a lighting system configured to project a light beam into the PBS such that it exits the output aperture surface of the PBS, enters the end surface of the optical waveguide, and exits the optical waveguide via a plurality of partially reflecting facets;a light imager configured to monitor parallelism between first and second portions of the light beam that have exited the optical waveguide;a cure system configured to secure the optical waveguide to the PBS; anda processing system configured to:cause the movement system to move the optical waveguide relative to the PBS; andresponsive to determining, via the light imager, that the first and second portions of the light beam that have exited the optical waveguide are parallel, cause the cure system to secure the optical waveguide to the PBS.

12. The apparatus of claim 11, wherein:the apparatus further comprises an interface imager configured to monitor a distance between the major surface of the optical waveguide and the first lens surface of the PBS; and the processing system is further configured to secure the optical waveguide to the PBS responsive to determining, via the interface imager, that the major surface of the optical waveguide is at a same level or within a threshold distance of the first lens surface of the PBS.

13. The apparatus of claim 11, wherein:the lighting system is further configured to project the light beam into the PBS such that a portion of the light beam passes through a splitting component of the PBS, is reflected off a first reflecting lens that is coupled with the PBS, and is reflected off the splitting component to exit the PBS via the output aperture surface of the PBS; andthe first and second portions of the light beam that have exited the optical waveguide correspond to respective portions of the portion of the light beam that passed through the splitting component.Docket: SSMP 45896 (Lumus 00202-3US)14. The apparatus of claim 13, wherein the lighting system is further configured to project the light beam into the PBS such that the first portion of the light beam reflects off the first lens surface of the PBS prior to exiting the PBS.

15. The apparatus of claim 13, wherein:the movement system is further configured to orient a second reflecting lens proximate a second lens surface of the PBS;the lighting system is further configured to project another light beam into the PBS such that a first portion of the other light beam passes through the splitting component of the PBS, is reflected off the first reflecting lens, and is reflected off the splitting component to exit the output aperture surface of the PBS and a second portion of the other light beam is reflected by the splitting component, is reflected by the second reflecting lens, and passes through the splitting component to exit the output aperture surface of the PBS, wherein the first and second portions of the other light beam enter the end surface of the optical waveguide, and exit the optical waveguide via the plurality of partially reflecting facets;the light imager is further configured to monitor parallelism between the first and second portions of the other light beam that have exited the optical waveguide; andthe processing system is further configured to:cause the movement system to translate the second reflecting lens relative to the PBS; andresponsive to determining, via the light imager, that the first and second portions of the other light beam that have exited the optical waveguide are parallel, cause the cure system to secure the second reflecting lens to the PBS.

16. The apparatus of claim 15, wherein the lighting system is further configured to project the light beam into the PBS such the first portion of the light beam reflects off the first lens surface of the PBS prior to exiting the PBS.

17. The apparatus of claim 11, wherein:the lighting system is further configured to project the light beam into the PBS as aDocket: SSMP 45896 (Lumus 00202-3US)collimated light beam such that a first portion of the collimated light beam exits the output aperture surface of the PBS directly and another portion of the collimated light beam reflects off the first lens surface prior to exiting the output aperture surface; andthe first and second portions of the light beam that have exited the optical waveguide correspond to the first and second portions of the collimated light beam.

18. The apparatus of claim 17, wherein:the apparatus further comprises one or more shutters; andthe processing system is further configured to:cause the one or more shutters to block the first portion of the collimated light beam prior to the first portion of the collimated light beam entering the PBS;image, via the light imager, the second portion of the collimated light beam that exits the optical waveguide;cause the one or more shutters to block the second portion of the collimated light beam prior to the second portion of the collimated light beam entering the PBS;image, via the light imager, the first portion of the collimated light beam that has exited the optical waveguide; andmonitor parallelism between the first and second portions of the collimated light beam that exit the optical waveguide based on the imaged first and second portions of the collimated light beam that exit the optical waveguide.

19. The apparatus of claim 11, wherein causing the cure system to secure the optical waveguide to the PBS comprises causing a curing of an ultraviolet (UV)-cure adhesive disposed between the optical waveguide and the PBS.

20. A method comprising:orienting an optical waveguide relative to a polarizing beam-splitter (PBS) such that an intersection of a major surface and an end surface of the optical waveguide is proximate an intersection of a first lens surface and an output aperture surface of the PBS;projecting a light beam into the PBS such that a portion of the light beam passes throughDocket: SSMP 45896 (Lumus 00202-3US)a splitting component of the PBS, is reflected off a first reflecting lens that is coupled with the PBS, is reflected off the splitting component to exit the PBS via an output aperture surface of the PBS, enters the end surface of the optical waveguide, and exits the optical waveguide via a plurality of partially reflecting facets, wherein a first portion of the portion of the light beam that passed through the splitting component reflects off the first lens surface of the PBS prior to exiting the PBS and a second portion of the portion of the light beam that passed through the splitting component does not reflect off the first lens surface of the PBS prior to exiting the PBS;monitoring, via a light imager, parallelism between the first and second portions of the portion of the light beam that passed through the splitting component and exited the optical waveguide;moving the optical waveguide relative to the PBS; andresponsive to determining, via the light imager, that the first and second portions of the light beam that have exited the optical waveguide are parallel, securing the optical waveguide to the PBS.

Images