US-12620782-B2 - Optical methods for reducing point spread function in phase light modulator applications

Abstract

A system includes at least one laser configured to produce laser light and an optical element configured to produce shaped light responsive to receiving the laser light. The system also includes an optical phase modulator (OPM) optically coupled to the optical element, the OPM configured to modulate the shaped light to produce modulated light, where the optical element is configured to reduce a point spread function of the modulated light in a far field.

Inventors

• Alexander Lyubarsky
• Terry A. Bartlett
• Kristofer Oberascher

Assignees

• TEXAS INSTRUMENTS INCORPORATED

Dates

Publication Date

20260505

Application Date

20221223

Claims (19)

1. 1 . A system comprising: at least one laser configured to produce laser light; an optical element configured to produce shaped light responsive to receiving the laser light; an optical phase modulator (OPM) optically coupled to the optical element, the OPM configured to modulate the shaped light to produce modulated light; a dichroic mirror optically coupled to the OPM; a reflective phosphor optically coupled to the dichroic mirror; and a reflective diffuser optically coupled to the dichroic mirror.
2. 2 . The system of claim 1 , wherein the optical element is an optical waveguide.
3. 3 . The system of claim 2 , wherein the optical waveguide comprises one of an optical fiber bundle, an array of rectangular light guides, and an optical waveguide comprising core and a low index cladding around the core.
4. 4 . The system of claim 2 , wherein the optical waveguide comprises: an integrator rod; and a variable aperture optically coupled to the integrator rod.
5. 5 . The system of claim 1 , wherein the at least one laser comprises a laser array, and wherein the optical element comprises: a fast-axis collimator (FAC) lens; and a slow-axis collimator (SAC) lens optically coupled to the FAC lens.
6. 6 . The system of claim 1 , wherein the at least one laser is a laser array comprising: first rows of lasers configured to produce a first portion of the laser light having a first characteristic; and second rows of lasers configured to produce a second portion of the laser light having a second characteristic different than the first characteristic, and wherein the optical element comprises: a mirror optically coupled to the second rows of lasers, the mirror configured to reflect the first portion of the laser light to produce reflected light; and an optical combining element optically coupled to the first row of lasers and to the mirror, the optical combining element configured to: transmit the first portion of the laser light having the first characteristic; and reflect the reflected light having the second characteristic.
7. 7 . The system of claim 1 , wherein the at least one laser is a laser array having a first number of rows, and wherein the optical element comprises a mirror having a second number of mirror segments, the second number the same as the first number, and the mirror segments optically coupled to corresponding rows of lasers.
8. 8 . The system of claim 1 , wherein the at least one laser is a laser array, and the optical element comprises a cylindrical lens.
9. 9 . The system of claim 1 , wherein the at least one laser comprises a laser diode configured to produce a first portion of the laser light and a laser array configured to produce a second portion of the laser light, and wherein the optical element comprises an optical combining element configured to combine the first portion of the laser light and the second portion of the laser light.
10. 10 . The system of claim 1 , wherein the at least one laser comprises a first laser array and a second laser array, and wherein the optical element comprises: a first fast-axis collimator (FAC) lens optically coupled to the first laser array; a first slow-axis collimator (SAC) lens optically coupled to the first FAC lens; a second FAC lens optically coupled to the second laser array; a second SAC lens optically coupled to the second FAC lens; and a polarizing beam splitter (PBS) optically coupled to the first FAC lens, the second FAC lens, the first SAC lens, and the second FAC lens.
11. 11 . A system comprising: a first laser assembly configured to produce first light having a first characteristic; a second laser assembly configured to produce second light having a second characteristic different than the first characteristic; an optical combining element optically coupled to the first laser assembly and to the second laser assembly, the optical combining element configured to combine the first light having the first characteristic and to the second light having the second characteristic to produce combined light comprising the first light and the second light; an optical phase modulator (OPM) optically coupled to the optical combining element, the OPM configured to modulate the combined light to produce modulated light; a first fast-axis collimator (FAC) lens optically coupled to the first laser assembly; a first slow-axis collimator (SAC) lens optically coupled to the first FAC; a second FAC lens optically coupled to the second laser assembly; and a second SAC lens optically coupled to the second FAC.
12. 12 . The system of claim 11 , wherein the first laser assembly comprises a laser array and the second laser assembly comprises a single laser diode.
13. 13 . The system of claim 11 , wherein the optical combining element is a first PBS, the first characteristic is a first polarization, the second characteristic is a second polarization, and the combined light is first combined light, the system further comprising: a second PBS optically coupled to the OPM, the second PBS configured to transmit a first portion of the modulated light having the first polarization and to reflect a second portion of the modulated light having the second polarization; first relay optics optically coupled to the second PBS, the first relay optics configured to transmit the first portion of the modulated light as first path light; a first mirror optically coupled to the second PBS, the first mirror configured to reflect the second portion of the modulated light as first reflected light; second relay optics optically coupled to the first mirror, the second relay optics configured to transmit the first reflected light as second path light; a second mirror optically coupled to the second relay optics, the second mirror configured to reflect the second path light as second reflected light; and a third PBS optically coupled to the second mirror and to the second relay optics, the second PBS configured to transmit the first path light and to reflect the second reflected light.
14. 14 . The system of claim 13 , further comprising: a dichroic mirror optically coupled to the third PBS; a reflective phosphor optically coupled to the dichroic mirror; and a reflective diffuser optically coupled to the dichroic mirror.
15. 15 . The system of claim 11 , wherein the first laser assembly comprises a first laser array and the second laser assembly comprises a second laser array.
16. 16 . The system of claim 11 , further comprising a birefringent prism optically coupled to the OPM.
17. 17 . A system comprising: at least one laser configured to produce laser light; an optical element configured to produce shaped light responsive to receiving the laser light; an optical phase modulator (OPM) optically coupled to the optical element, the OPM configured to modulate the shaped light to produce modulated light, wherein the optical element is configured to reduce a point spread function of the modulated light in a far field; a spatial light modulator (SLM) optically coupled to the OPM, the SLM configured to produce an image based on the modulated light; and a birefringent prism optically coupled to the OPM.
18. 18 . The system of claim 17 , wherein the optical element is an optical waveguide.
19. 19 . The system of claim 17 , wherein the at least one laser comprises at least one first laser configured to produce a first portion of the laser light having a first characteristic and at least one second laser configured to produce a second portion of the laser light having a second characteristic different than the first characteristic, and wherein the optical element comprises an optical combining element optically coupled to the at least one first laser and to the at least one second laser, the optical combining element configured to combine the first portion of the laser light having the first characteristic and the second portion of the laser light having the second characteristic.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to U.S. Provisional Patent Application No. 63/366,895, filed on Jun. 23, 2022, and entitled “OPTICAL METHODS FOR REDUCING POINT SPREAD FUNCTION IN PHASE LIGHT MODULATOR APPLICATIONS” and to U.S. Provisional Patent Application No. 63/322,272, filed on Mar. 22, 2022, and entitled “HIGH-BRIGHTNESS, HIGH-DYNAMIC-RANGE IMAGE PROJECTION WITH IMPROVED PHASE SPATIAL LIGHT MODULATOR BACKLIGHT RESOLUTION,” which Applications are hereby incorporated herein by reference in their entireties. TECHNICAL FIELD The present application relates in general to optical systems, and, in particular, to a system and method for optical phase modulators. BACKGROUND In many applications, for example automotive or display applications, it is desirable to provide optical phase modulation. Optical phase modulation may be used in high dynamic range (HDR) applications, automotive headlights, light detection and ranging (LIDAR) applications, and other display applications. SUMMARY An example includes a system including at least one laser configured to produce laser light and an optical element configured to produce shaped light responsive to receiving the laser light. The system also includes an optical phase modulator (OPM) optically coupled to the optical element, the OPM configured to modulate the shaped light to produce modulated light, where the optical element is configured to reduce a point spread function of the modulated light in a far field. Another example includes a system including a first laser assembly configured to produce first light having a first characteristic and a second laser assembly configured to produce second light having a second characteristic different than the first characteristic. The system also includes an optical combining element optically coupled to the first laser assembly and to the second laser assembly, the optical combining element configured to combine the first light having the first characteristic and to the second light having the second characteristic to produce combined light including the first light and the second light. Additionally, the system includes an optical phase modulator (OPM) optically coupled to the optical combining element, the OPM configured to modulate the combined light to produce modulated light, where the system is configured to reduce a point spread function of the modulated light in a far field. An additional example includes a system including at least one laser configured to produce laser light and an optical element configured to produce shaped light responsive to receiving the laser light. The system also includes an optical phase modulator (OPM) optically coupled to the optical element, the OPM configured to modulate the shaped light to produce modulated light, where the optical element is configured to reduce a point spread function of the modulated light in a far field. Additionally, the system includes a spatial light modulator (SLM) optically coupled to the OPM, the SLM configured to produce an image based on the modulated light. BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the illustrative examples of aspects of the present application that are described herein and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: FIGS. 1A-C illustrate example optical projection systems; FIG. 2A illustrates another example optical projection system, FIG. 2B illustrates an example edge emitting laser diode, and FIG. 2C illustrates example beam shaping optics; FIG. 3 illustrates an additional example optical projection system; FIGS. 4A-B illustrate the operation of an example optical projection system; FIGS. 5A-I illustrates example optical waveguides; FIG. 6A illustrates an example optical projection system and FIGS. 6B-C illustrate point spread functions in the far field of an example optical projection system; FIG. 7A illustrates a laser light source, FIG. 7B illustrates a laser beam footprint for a laser light source, and FIG. 7C illustrates a point spread function in the far field for an example laser light source; FIG. 8A illustrates an example laser light source, FIG. 8B illustrates a laser beam footprint for an example laser light source, and FIG. 8C illustrates a point spread function in the far field for an example laser light source, FIG. 8D illustrates another laser beam footprint for an example laser light source, and FIG. 8E illustrates another point spread function in the far field for an example laser light source; FIG. 9 illustrates an additional example laser light source; FIG. 10A illustrates an example light source, FIG. 10B illustrates a laser beam footprint for an example light source, FIG. 10C illustrates an example point spread function in the far field for an example light source, and FIG. 10D illustrates another example light source; FIG. 11A illustrates an example laser