# US 2022/0045480 A1 · Efficient generation of spatially-restructurable high-order hg-modes in a laser cavity > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0045480 A1 - Document ID: US20220045480A1 - Status: Published application - Kind: A1 - Application number: 17/432,307 - Filed: 2020-02-18 - Published: 2022-02-10 - Earliest claimed: 2019-02-19 - Assignees: Arizona Board of Regents on Behalf of the University of Arizona - Applicants: Arizona Board of Regents on Behalf of the University of Arizona - Inventors: Chris Hessenius; Mahmoud Fallahi; Michal L. Lukowski - Web page: https://patentgrep.com/patent/US20220045480A1 ## CPC - H01S 5/041: {Optical pumping} - H01S 3/0804: Transverse or lateral modes - H01S 3/08045: Single-mode emission - H01S 3/082: defining a plurality of resonators, e.g. for mode selection or suppression - H01S 5/0604: {comprising a non-linear region, e.g. generating harmonics of the laser frequency} - H01S 5/0651: {Mode control} - H01S 5/1021: {Coupled cavities (H01S5/14 takes precedence)} - H01S 5/18361: {Structure of the reflectors, e.g. hybrid mirrors} - H01S 3/0092: {Nonlinear frequency conversion, e.g. second harmonic generation [SHG] or sum- or difference-frequency generation outside the laser cavity (nonlinear frequency conversion per se G02F1/35)} - H01S 5/005: {Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping (H01S5/026, H01S5/18388 take precedence)} - H01S 5/0092: {for nonlinear frequency conversion, e.g. second harmonic generation [SHG] or sum- or difference-frequency generation outside the laser cavity} - H01S 5/02469: {Passive cooling, e.g. where heat is removed by the housing as a whole or by a heat pipe without any active cooling element like a TEC} - H01S 5/141: {using a wavelength selective device, e.g. a grating or etalon (H01S5/146 takes precedence)} - H01S 5/183: having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL] - H01S 5/4062: {with an external cavity or using internal filters, e.g. Talbot filters} - H01S 2301/20: Lasers with a special output beam profile or cross-section, e.g. non-Gaussian - 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 vertical external cavity surface emitting laser (VECSEL) based system in a linear single cavity configuration is configured to deliver light in higher-order Hermite-Gaussian transverse modes with Watt-level output power. Simultaneous and independent lasing of spatially-restructurable multiple high-order transverse modes that are collinearly-propagating at the output of such laser cavity is facilitated with the use of an optical pumping scheme devised to control positions of location at which the gain medium of the system is pumped (e.g., locations of focal spots of multiple pump beams on the gain-medium chip). An external astigmatic mode converter is utilized to convert such high-order Hermite-Gaussian modes into corresponding Laguerre-Gaussian modes. ## Claims ### Claim 1 A laser system, comprising: a linear laser cavity having a laser cavity axis and defined by first and second reflectors; a laser gain medium chip containing said first reflector; the second reflector dimensioned to have a center of curvature of the second reflector at an axial point of the first reflector; multiple pump channels configured to deliver pumping energy to the laser gain medium chip at respectively-corresponding multiple initial locations of a surface of the laser gain medium chip in a fashion that allows for spatially-varying said multiple initial locations; and a mechanism configured to cause, during the operation of the laser system, a change of first and second of said multiple initial locations to respectively-corresponding third and fourth locations. ### Claim 2 (depends on 1) The laser system according to claim 1, further comprising an astigmatic mode converter (AMC) system outside of the laser cavity on the laser cavity axis. ### Claim 3 (depends on 2) The laser system according to claim 2, wherein the AMC system is configured to have at least one of optical elements of the AMC system to be rotated about the laser cavity axis. ### Claim 4 (canceled) ### Claim 5 (depends on 1) The laser system according to claim 1, wherein at least one of the following conditions is satisfied: a) the first and second of said multiple initial locations are positioned in said surface symmetrically with respect to the laser axis; and b) the third and fourth locations are positioned in said surface symmetrically with respect to the laser cavity axis. ### Claim 6 (depends on 1) The laser system according to claim 1, wherein a number of said multiple initial locations is even, and wherein said multiple initial locations form pairs of initial locations, initial locations in a first pair are defined on a first axis, initial locations in a second pair are defined on a second axis, the first and second axes being transverse to one another. ### Claim 7 (depends on 6) The laser system according to claim 6, wherein the first and second axes are perpendicular to one another. ### Claim 8 (depends on 6) The laser system according to claim 6, further comprising a mechanism configured to re-orient said multiple pump channels to change at least one of i) a first spatial separation between the axial point of the first reflector and at least one of locations in the first pair; and ii) a second spatial separation between the axial point of the first reflector and at least one of locations in the second pair independently from one another. ### Claim 9 (depends on 1) The laser system according to claim 1, said laser system being devoid of an intracavity optical element that is configured to introduce preferential optical loss to a given laser mode supported by said laser cavity. ### Claim 10 (depends on 1) The laser system according to claim 1, wherein the first reflector is a distributed Bragg reflector (DBR) of the laser gain medium chip. ### Claim 11 (depends on 1) The laser system according to claim 1, wherein said laser cavity does not contain any intracavity element. ### Claim at position 12 -26. (canceled) ### Claim 27 A laser system, comprising: a linear laser cavity having a laser cavity axis and defined by first and second reflectors; a laser gain medium chip containing said first reflector; the second reflector dimensioned to have a center of curvature of the second reflector at an axial point of the first reflector, and multiple pump channels configured to deliver pumping energy to the laser gain medium chip at respectively-corresponding multiple initial locations of a surface of the laser gain medium chip in a fashion that allows for spatially-varying said multiple initial locations wherein a number of said multiple initial locations is even, wherein said multiple initial locations form pairs of initial locations, initial locations in a first pair are defined on a first axis, initial locations in a second pair are defined on a second axis, the first and second axes being transverse to one another. ### Claim 28 (depends on 27) The laser system according to claim 27, further comprising an astigmatic mode converter (AMC) system outside of the laser cavity on the laser cavity axis. ### Claim 29 (depends on 28) The laser system according to claim 28, wherein the AMC system is configured to have at least one of optical elements of the AMC system to be rotated about the laser cavity axis. ### Claim 30 (depends on 27) The laser system according to claim 27, wherein the first and second axes are perpendicular to one another. ### Claim 31 (depends on 27) The laser system according to claim 27, further comprising a mechanism configured to re-orient said multiple pump channels to change at least one of i) a first spatial separation between the axial point of the first reflector and at least one of locations in the first pair; and ii) a second spatial separation between the axial point of the first reflector and at least one of locations in the second pair independently from one another. ### Claim 32 (depends on 27) The laser system according to claim 27, said laser system being devoid of an intracavity optical element that is configured to introduce preferential optical loss to a given laser mode supported by said laser cavity. ### Claim 33 (depends on 27) The laser system according to claim 27, wherein the first reflector is a distributed Bragg reflector (DBR) of the laser gain medium chip. ### Claim 34 (depends on 27) The laser system according to claim 27, wherein at least one of the following conditions is satisfied: a) the first and second of said multiple initial locations are positioned in said surface symmetrically with respect to the laser axis; and b) the third and fourth locations are positioned in said surface symmetrically with respect to the laser cavity axis.