# US 12,001,028 B2 · Speckle-suppressing lighting system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,001,028 B2 - Document ID: US12001028B2 - Status: Granted - Kind: B2 - Application number: 17/953,129 - Filed: 2022-09-26 - Published: 2023-03-30 - Granted: 2024-06-04 - Earliest claimed: 2021-09-24 - Assignees: Trustees of Dartmouth College - Applicants: The Trustees of Dartmouth College - Inventors: Xiaoxin Wang; Charles J. Carver, Jr.; Eric R. Fossum; Jifeng Liu; Xia Zhou; Nicholas R. Shade - Web page: https://patentgrep.com/patent/US12001028B2 ## CPC - G02B 27/48: Laser speckle optics - F21V 13/02: Combinations of only two kinds of elements - G02B 6/0006: {Coupling light into the fibre (in general G02B6/4298)} - G02B 6/0008: {the light being emitted at the end of the fibre} - G02B 6/0046: {Tapered light guide, e.g. wedge-shaped light guide} - G02B 6/0096: {the lights guides being of the hollow type} - G02B 19/0019: {having reflective surfaces only (e.g. louvre systems, systems with multiple planar reflectors)} - G02B 19/0057: {in the form of a laser diode array, e.g. laser diode bar (semiconductor laser arrays with beam combining arrangement H01S5/4012)} - G02B 27/0927: {Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat} - G02B 27/0994: {Fibers, light pipes (optical fibers per se G02B6/02)} - F21Y 2115/30: Semiconductor lasers - G02B 5/0278: {used in transmission} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - F21V: FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR - F21Y: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED ## Abstract A speckle-suppressing lighting system includes an optical waveguide, a first solid-state light source, a second solid-state light source, and a diffuser. The optical waveguide has a proximal end and a distal end. At least part of the diffuser is between the proximal end and the distal end. The first solid-state light source is optically coupled to the optical waveguide near the proximal end, and emits a first light beam that propagates toward the distal end and has a first center wavelength. The second solid-state light source is optically coupled to the optical waveguide near the proximal end, and emits a second light beam that propagates toward the distal end and has a second center wavelength differing from the first center wavelength. The diffuser diffuses the first light beam and the second light beam. ## Claims ### Claim 1 A speckle-suppressing lighting system comprising: an optical waveguide having a proximal end, a distal end, and being a solid volume of material having a proximal base surface, a distal base surface, an outer lateral-surface therebetween; a first solid-state light source, optically coupled to the optical waveguide near the proximal end, that emits a first light beam that propagates toward the distal end and has a first center wavelength; a second solid-state light source, optically coupled to the optical waveguide near the proximal end, that emits a second light beam that propagates toward the distal end and has a second center wavelength differing from the first center wavelength; a diffuser, at least part of which is between the proximal end and the distal end, that diffuses the first light beam and the second light beam; and an interior-facing diffuse reflective coating on the outer lateral-surface. ### Claim 2 (depends on 1) The speckle-suppressing lighting system of claim 1, at least one of the first solid-state light source and the second solid-state light source being a laser. ### Claim 3 (depends on 1) The speckle-suppressing lighting system of claim 1, a shape of the optical waveguide being a frustum that includes at least three trapezoidal lateral-surfaces spanning between the proximal end and the distal end. ### Claim 4 (depends on 1) The speckle-suppressing lighting system of claim 1, the diffuser being a diffuser rod. ### Claim 5 (depends on 1) The speckle-suppressing lighting system of claim 1, the diffuser including multiple diffuser plates. ### Claim 6 (depends on 1) The speckle-suppressing lighting system of claim 1, the distal end being a distal surface of the optical waveguide, the speckle-suppressing lighting system further comprising a diffuser plate on the distal surface. ### Claim 7 (depends on 1) The speckle-suppressing lighting system of claim 1, the distal end being a distal surface of the optical waveguide, the speckle-suppressing lighting system further comprising a total-internal-reflection lens on the distal surface. ### Claim 8 (depends on 1) The speckle-suppressing lighting system of claim 1, further comprising at least one of (i) a first optical waveguide that couples the first solid-state light source to the proximal end, and (ii) a second optical waveguide that couples the second solid-state light source to the proximal end. ### Claim 9 (depends on 8) The speckle-suppressing lighting system of claim 8, each of the first optical waveguide and the second optical waveguide being an optical fiber. ### Claim 10 (depends on 8) The speckle-suppressing lighting system of claim 8, each of the first optical waveguide and the second optical waveguide being a light pipe. ### Claim 11 A speckle-suppressing lighting system comprising: an optical waveguide that (i) has a proximal end and a distal end that includes a distal surface of the optical waveguide and (ii) is hollow and includes an inner lateral-surface that spans between the proximal end and the distal end, and defines an aperture in the proximal end and the distal end; a reflective coating on the inner lateral-surface; a total-internal-reflection lens on the distal surface; a first solid-state light source, optically coupled to the optical waveguide near the proximal end, that emits a first light beam that propagates toward the distal end and has a first center wavelength; a second solid-state light source, optically coupled to the optical waveguide near the proximal end, that emits a second light beam that propagates toward the distal end and has a second center wavelength differing from the first center wavelength; and a diffuser, at least part of which is between the proximal end and the distal end, that diffuses the first light beam and the second light beam. ### Claim 12 (depends on 11) The speckle-suppressing lighting system of claim 11, the optical waveguide including an outer lateral-surface that spans between the proximal end and the distal end, the proximal end and the distal end being, respectively, a first annular surface and a second annular surface between the inner lateral-surface and the outer lateral-surface. ### Claim 13 (depends on 11) The speckle-suppressing lighting system of claim 11, in a cross-sectional plane through both the inner lateral-surface and parallel to a plane of one of the proximal end or the distal end, a shape of the inner lateral-surface being one of circular, elliptical, polygonal, and any combination thereof. ### Claim 14 (depends on 11) The speckle-suppressing lighting system of claim 11, an output width of the distal end exceeding an input width of the proximal end such that the optical waveguide has a tapered cross-section in a cross-sectional plane that intersects the proximal end, the distal end, and opposite sides of the inner lateral-surface.