# US 2024/0201485 A1 · Correction optical elements for coherent beam combining systems and systems and methods for coherent beam combining using same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2024/0201485 A1 - Document ID: US20240201485A1 - Status: Published application - Kind: A1 - Application number: 18/403,769 - Filed: 2024-01-04 - Published: 2024-06-20 - Earliest claimed: 2021-07-08 - Assignees: Elbit Systems Electro-Optics Elop Ltd. - Applicants: Elbit Systems Electro-Optics - Elop Ltd. - Inventors: Zeev SCHIFFER; Daniel LEVY; Ran Zvi MAROM - Web page: https://patentgrep.com/patent/US20240201485A1 ## CPC - G02B 27/0025: {for optical correction, e.g. distorsion, aberration} - G02B 5/045: {Prism arrays} - G02B 6/262: {Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements} - G02B 6/32: having lens focusing means {positioned between opposed fibre ends (with lens being an integral part of the single fibre end G02B6/262)} - G02B 27/0905: {Dividing and/or superposing multiple light beams} - G02B 27/4216: {correcting geometrical aberrations} - G02B 3/0056: {arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses (G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085)} - G02B 5/0231: {the surface having microprismatic or micropyramidal shape (macroscopic prism arrays G02B5/045)} - H01S 3/1301: {in optical amplifiers} - H01S 3/1305: {Feedback control systems} - H01S 3/1307: {Stabilisation of the phase} - H01S 3/2383: {Parallel arrangements} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL ## Abstract A correction optical element (COE) for a multi-channeled coherent beam combining (CBC) system that uses a fiber array comprising multiple optical fibers and a single collimation array comprising multiple collimating lenses, for coherent combining of a corresponding array of optical beams directed through the fiber array. The COE is configured for customized and segmented correction of collimation-based optical aberrations, caused at least due to misalignments between each corresponding optical fiber's Lij output end and a center of a corresponding collimating lens Lij. ## Claims ### Claim at position 1 1-35. (canceled) ### Claim 36 A correction optical element (COE) for a multi-channeled coherent beam combining (CBC) system that uses a fiber array comprising multiple optical fibers and a single collimation array comprising multiple collimating lenses each configured only for collimation of an incoming optical beam, for coherent combining of a corresponding array of optical beams directed through the fiber array, wherein each pair of: a collimating lens of the collimation array and a corresponding optical fiber of the fiber array, defines a channel ij, wherein the COE is custom-fabricated for segmented correction of optical aberrations of the specific single CBC system by having an array of correction segments, each correction segment CSij in the array of correction segments, being customized in location and configuration to correct specific and premeasured one or more optical aberrations of a corresponding output optical beam Bij outputted from each corresponding pair of a collimation lens Lij and a corresponding optical fiber Fij, wherein the COE is configured for customized and segmented correction of collimation-based optical aberrations, caused at least due to misalignment between each corresponding optical fiber's Fij output end and a center of a corresponding collimating lens Lij, wherein the correction of the optical aberrations of all channels of the system, is done optically and simultaneously by the COE, and wherein the COE is located adjacently to and before or after the collimation array, such that no optical element is placed therebetween that is configured to change beam profile of optical beams. ### Claim 37 (depends on 36) The COE of claim 36, wherein the COE is configured to segmentally correct, for each output optical beam Bij, any one or more optical aberrations of: pointing errors; focusing/collimation errors; wave-front aberrations; high-order three dimensional aberrations, spatial distribution errors; comatic aberrations; field curvature aberrations, cylinder aberrations; smile errors, manufacturing errors, errors in spaces between collimating lenses in the collimation array. ### Claim 38 (depends on 36) The COE of claim 36, wherein the COE is made of a monolithic piece being customized to have each correction segment CSij thereof differently custom shaped to correct one or more aberrations of the corresponding output optical beam Bij of the respective channel ij. ### Claim 39 (depends on 36) The COE of claim 36, being further designed for a CBC system in which the optical fibers are connected to an input surface of an endcapping element. ### Claim 40 (depends on 39) The COE of claim 39, wherein the COE is integrally connected or configured over an output surface of the collimation array, the output curved surface comprising lens-shaped curved bulges each bulge having a custom-designed correction embossment or etching, such that each of the optical beams exiting an output surface of the endcapping element are both collimated and corrected. ### Claim 41 (depends on 39) The COE of claim 39, wherein the COE is integrally or non-integrally connected to an input surface of the collimation array, wherein bulges of lenses of the collimation array form the output surface of the COE and custom-shaped correction segments are located over an input surface of the COE, facing an output surface of the endcapping element. ### Claim 42 (depends on 39) The COE of claim 39, wherein the COE is embedded in the collimation array and the endcapping element of the CBC system, forming a single monolithic coherent beam combination, endcapping and correction element by having an output surface of the endcapping element integrally connected to an input surface of the collimation array and an output surface of the collimation array having a correcting 3D design embossed or debossed thereover for performing combined customized and segmented collimation and aberration correction of each optical beam. ### Claim 43 (depends on 36) The COE of claim 36, wherein the COE is configured for correcting optical aberrations of a multi-channel CBC system using high power fiber lasers or fiber amplifiers. ### Claim 44 A method for fabricating a correction optical element (COE) for a multi-channel coherent beam combining (CBC) system having an array of channels, using a fiber array, which is an array of optical fibers, an endcapping element connected at an input side thereof to the array of optical fibers and a collimation array comprising multiple collimating lenses each collimating lens being configured only for collimation of an incoming optical beam, for coherent combining of an array of input optical beams outputted by the endcapping element, the method comprising: measuring one or more optical aberrations Aij of each channel ij of the array of channels of the CBC system, based on measurement of characteristics of a wavefront of each output optical beam Bij of each channel Cij, outputted from a respective lens Lij of the collimation array which is connected to a respective optical fiber Fij; determining, for each segment CSij of the COE to be fabricated, a required correction design for correcting all measured optical aberrations of the respective correcting segment CSij, for the specific CBC system and for a particular location and positioning of the COE to be fabricated; fabricating a COE having an array of segments, by configuring each segment of the COE according to its respective required correction design; placing the COE at a determined positioning for optimal aberrations correction such that each correction segment CSij of the COE is positioned in an optimal positioning in respect to the output optical beam Bij; and using the COE to simultaneously correct optical aberrations of all segments of the CBC system; wherein the COE is configured for customized and segmented correction of optical aberrations, caused due to misalignments between a respective optical fiber's output end and a center of a corresponding collimating lenslet Lij of the collimation array of the specific CBC system, and wherein the COE is located adjacently to and before or after the collimation array, such that no optical element is placed therebetween that is configured to change beam profile of optical beams. ### Claim 45 (depends on 44) The method of claim 44, wherein the COE is configured to segmentally correct one or more optical aberrations, for each output optical beam Bij, of: pointing errors; focusing/collimation errors; wave-front aberrations; high-order three dimensional aberrations, spatial distribution errors; comatic aberrations; field curvature aberrations, cylinder aberrations; smile errors, manufacturing errors, errors in spaces between collimating lenses in the collimation array. ### Claim 46 (depends on 44) The method of claim 44, wherein each output optical beams Bij, measured for determination of its respective one or more aberrations is directed from a respective optical fiber Fij, through the endcapping element towards a correction input surface of the COE, wherein the collimation array is formed as an output surface of the COE. ### Claim 47 (depends on 44) The method of claim 44, further comprising directing light emanating from a single light source to the fiber array, using one or more optical splitting elements. ### Claim 48 (depends on 44) The method of claim 44, wherein the one or more optical aberrations of each channel ij, for all channels of the CBC system are measured simultaneously or separately channel by channel, using one or more optical detectors and a processing and control unit, configured to receive and analyze output data outputted by the one or more optical detectors, in order to determine required correction for each channel ij of the CBC system. ### Claim 49 (depends on 48) The method of claim 48, wherein the one or more optical detectors comprise one or more of: a camera, a charged coupled device (CCD), an array of photodiodes or photo detectors, M×N photo detectors each coupled to a different focusing lens or lenslet for separately measuring optical characteristics including the one or more optical aberrations for each channel ij. ### Claim 50 (depends on 44) The method of claim 44, wherein the COE is configured to be essentially positioned in parallel to the collimation array. ### Claim 51 (depends on 44) The method of claim 44, wherein each correction segment CSij design is determined by measuring one or more wavefront characteristics of each beam Bij using the one or more optical detectors and generating a three-dimensional model of the correction segment CSij of the respective channel ij, based on the wavefront characteristics. ### Claim 52 (depends on 51) The method of claim 51, wherein the 3D design of each correction segment CSij is a 3D mirror image of the wavefront of the beam Bij of the corresponding channel ij. ### Claim 53 A system for coherent beam combining (CBC) comprising at least: at least one light source for irradiating light in a narrow wavelength band; a fiber array, which is an array of optical fibers configured to guide light emanating from the at least one light source forming an array of input optical beams; a collimation array, which is an array of collimating lenses, each collimating lens being configured only for collimation of an incoming optical beam; and a correction optical element (COE) that is customized for segmented correction of optical aberrations of the specific CBC system, the COE comprising an array of correction segments, each correction segment CSij being configured to correct specific and premeasured one or more optical aberrations of a corresponding output beam Bij emanating from a corresponding optical fiber Fij of a respective ij channel, wherein the COE is configured customized and segmented correction of optical aberrations, caused at least due to misalignments between a respective optical fiber's output end and a center of a corresponding collimating lens Lij of the collimation array of the specific CBC system, wherein the correction of optical aberrations of all channels is done optically and simultaneously, and wherein the COE is located adjacently to and before or after the collimation array, such that no optical element is placed therebetween that is configured to change beam profile of optical beams. ### Claim 54 (depends on 23, 24) The CBC system of any one or more of claims 23 to 24 further comprising: one or more optical detectors located and configured to detect optical characteristics of a coherently combined output beam that has been combined by the collimation array and corrected by the COE; a processing and control subsystem (PCS), configured to receive output data from the one or more optical detectors and analyze the received output data to measure one or more CBC system performances characteristics. ### Claim 55 (depends on 54) The CBC system of claim 54 further comprising a synchronization module for synchronizing phase and/or polarization of each channel ij such that all phases and/or polarizations of all channels are synchronized, using corresponding a phase synchronization module including an array of phase shifters and/or a polarization synchronization module including an array of polarization controllers.