# US 2021/0242653 A1 · Optically-pumped semiconductor waveguide amplifier > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0242653 A1 - Document ID: US20210242653A1 - Status: Published application - Kind: A1 - Application number: 17/164,652 - Filed: 2021-02-01 - Published: 2021-08-05 - Earliest claimed: 2020-01-30 - Assignees: University of Central Florida Research Foundation, Inc. - Applicants: University of Central Florida Research Foundation, Inc. - Inventors: Guifang Li; Patrick LiKamWa - Web page: https://patentgrep.com/patent/US20210242653A1 ## CPC - H01S 3/06754: {Fibre amplifiers (H01S3/06708 takes precedence)} - H01S 5/50: Amplifier structures not provided for in groups H01S5/02 - H01S5/30 - H01S 3/06716: {Fibre compositions (per se C03C13/04)or doping with active elements (lasing materials in general H01S3/14)} - H01S 3/094011: {with bidirectional pumping, i.e. with injection of the pump light from both two ends of the fibre} - H01S 3/1628: {characterised by a semiconducting matrix} - H01S 5/041: {Optical pumping} - H01S 5/1032: {Coupling to elements comprising an optical axis that is not aligned with the optical axis of the active region} - H01S 5/026: Monolithically integrated components, e.g. waveguides, monitoring photo-detectors, drivers (stabilisation of output H01S5/06) - H01S 5/101: {Curved waveguide (H01S5/1243 takes precedence)} - H01S 5/1014: {Tapered waveguide, e.g. spotsize converter (H01S5/1064 takes precedence)} - H01S 5/1039: {Details on the cavity length} - H01S 5/22: having a ridge or stripe structure - H01S 5/34306: {emitting light at a wavelength longer than 1000nm, e.g. InP based 1300 and 1500nm lasers} - H01S 5/34313: {with a well layer having only As as V-compound, e.g. AlGaAs, InGaAs} - H01S 5/34333: {with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser} - H01S 5/4031: {Edge-emitting structures} - H01S 5/5018: {using two or more amplifiers or multiple passes through the same amplifier} - 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 power semiconductor waveguide optical amplifier (P-SWA) may include an amplifier waveguide with an invertible core formed from one or more undoped heterogeneous semiconductor layers and one or more cladding layers surrounding one or more sides of the invertible core formed as one or more undoped semiconductor layers. Pump light may be coupled into the amplifier waveguide to induce the population inversion in the invertible core. Signal light may further be coupled into the amplifier waveguide and may be amplified as it propagates through the amplifier waveguide. The signal light may then exit the amplifier waveguide as amplified signal light. ## Claims ### Claim 1 An optical amplifier comprising: an amplifier waveguide comprising: an invertible core formed from one or more undoped heterogeneous semiconductor layers; and one or more cladding layers surrounding one or more sides of the invertible core formed as one or more undoped semiconductor layers, wherein pump light from one or more pump sources is coupled into the amplifier waveguide to induce a population inversion in the invertible core, wherein signal light propagates through the amplifier waveguide, wherein the signal light is amplified as it propagates through the amplifier waveguide and exits the amplifier waveguide as amplified signal light. ### Claim 2 (depends on 1) The optical amplifier of claim 1, wherein the invertible core comprises: a quantum well core including one or more quantum well layers, wherein the one or more quantum well layers provide quantum confinement of carriers along a single dimension. ### Claim 3 (depends on 2) The optical amplifier of claim 2, wherein the quantum well core comprises: a multiple quantum well (MQW) core, wherein the one or more quantum well layers comprise two or more quantum well layers, wherein the two or more quantum well layers are separated by one or more barrier layers. ### Claim 4 (depends on 3) The optical amplifier of claim 3, wherein the two or more quantum well layers comprise at least five quantum well layers. ### Claim 5 (depends on 3) The optical amplifier of claim 3, wherein at least some of the two or more quantum well layers are strained to equalize a gain of the signal light with TM and TE polarizations within a selected tolerance. ### Claim 6 (depends on 5) The optical amplifier of claim 5, wherein the two or more quantum well layers are one of compressively strained or tensile strained, wherein the barrier layers are the other of compressively strained or tensile strained. ### Claim 7 (depends on 3) The optical amplifier of claim 3, wherein a carrier density associated with the population inversion in each of the two or more quantum well layers is constant within a selected tolerance. ### Claim 8 (depends on 2) The optical amplifier of claim 2, wherein the quantum well core comprises: a single quantum well core (SQW) formed as a single quantum well layer. ### Claim 9 (depends on 1) The optical amplifier of claim 1, wherein the invertible core comprises: a bulk undoped semiconductor core. ### Claim 10 (depends on 1) The optical amplifier of claim 1, wherein at least one of the one or more pump sources is an integrated pump laser comprising: a multilayer semiconductor structure integrated on a common substrate with the invertible core and the one or more cladding layers. ### Claim 11 (depends on 10) The optical amplifier of claim 10, wherein the pump light from the integrated pump laser is coupled into the invertible core through at least one of evanescent coupling or a tapered waveguide. ### Claim 12 (depends on 1) The optical amplifier of claim 1, wherein at least one of the one or more pump sources is external to the optical amplifier. ### Claim 13 (depends on 12) The optical amplifier of claim 12, wherein the pump light from at least one of the one or more pump sources is coupled into the amplifier waveguide through at least one of fiber coupling or free-space coupling. ### Claim 14 (depends on 1) The optical amplifier of claim 1, wherein the amplifier waveguide is bi-directionally pumped by the one or more pump sources. ### Claim 15 (depends on 1) The optical amplifier of claim 1, wherein the signal light is coupled into the amplifier waveguide from a passive waveguide integrated on a common substrate as the amplifier waveguide. ### Claim 16 (depends on 1) The optical amplifier of claim 1, wherein the signal light is coupled into the amplifier waveguide through at least one of fiber coupling or free-space coupling. ### Claim 17 An optical amplifier comprising: one or more pump sources configured to generate pump light, wherein the one or more pump sources comprise multilayer structures on a substrate; and an amplifier waveguide on the substrate comprising: an invertible core formed from one or more undoped heterogeneous semiconductor layers; and one or more cladding layers surrounding one or more sides of the invertible core formed as one or more undoped semiconductor layers, wherein the pump light is coupled into the amplifier waveguide to induce a population inversion in the invertible core, wherein signal light propagates through the amplifier waveguide, wherein the signal light is amplified as it propagates through the amplifier waveguide and exits the amplifier waveguide as amplified signal light. ### Claim 18 (depends on 17) The optical amplifier of claim 17, wherein the one or more pump sources include two or more pump sources. ### Claim 19 (depends on 18) The optical amplifier of claim 18, wherein the two or more pump sources are distributed along a length of the amplifier waveguide to provide two or more amplification stages. ### Claim 20 (depends on 17) The optical amplifier of claim 17, wherein a width of the amplifier waveguide adiabatically increases along a direction of propagation of the signal light. ### Claim 21 (depends on 17) The optical amplifier of claim 17, wherein the amplifier waveguide is disposed on top of at least one of the one or more pump sources. ### Claim 22 (depends on 21) The optical amplifier of claim 21, wherein the pump light from the at least one of the one or more pump sources is coupled into the amplifier waveguide through one of the one or more cladding layers by evanescent coupling. ### Claim 23 (depends on 17) The optical amplifier of claim 17, wherein the amplifier waveguide is disposed at a common height above the substrate as at least one of the one or more pump sources. ### Claim 24 (depends on 23) The optical amplifier of claim 23, wherein the pump light from the at least one of the one or more pump sources is coupled into the amplifier waveguide through one of the one or more cladding layers through a tapered waveguide. ### Claim 25 (depends on 17) The optical amplifier of claim 17, wherein at least one of the one or more pump lasers comprises: a laser diode. ### Claim 26 (depends on 17) The optical amplifier of claim 17, wherein the invertible core comprises: a quantum well core including one or more quantum well layers, wherein the one or more quantum well layers provide quantum confinement of carriers along a single dimension. ### Claim 27 (depends on 26) The optical amplifier of claim 26, wherein the quantum well core comprises: a multiple quantum well (MQW) core, wherein the one or more quantum well layers comprise two or more quantum well layers, wherein the two or more quantum well layers are separated by one or more barrier layers. ### Claim 28 (depends on 26) The optical amplifier of claim 26, wherein the quantum well core comprises: a single quantum well core (SQW) formed as a single quantum well layer. ### Claim 29 (depends on 26) The optical amplifier of claim 26, wherein at least some of the one or more quantum well layers are strained to equalize a gain of the signal light with TM and TE polarizations within a selected tolerance. ### Claim 30 (depends on 17) The optical amplifier of claim 17, wherein the invertible core comprises: a bulk undoped semiconductor core. ### Claim 31 A laser source comprising: a signal source configured to generate signal light, wherein the signal source comprises a multilayer structure on a substrate; one or more pump sources configured to generate pump light, wherein the one or more pump sources comprise multilayer structures on the substrate; and an amplifier waveguide on the substrate comprising: an invertible core formed from one or more undoped heterogeneous semiconductor layers; and one or more cladding layers surrounding one or more sides of the invertible core formed as one or more undoped semiconductor layers, wherein the pump light is coupled into the amplifier waveguide to induce a population inversion in the invertible core, wherein the signal light is coupled into the amplifier waveguide, wherein the signal light is amplified as it propagates through the amplifier waveguide and exits the amplifier waveguide as amplified signal light. ### Claim 32 (depends on 31) The laser source of claim 31, wherein the one or more pump sources include two or more pump sources. ### Claim 33 (depends on 32) The laser source of claim 32, wherein the two or more pump sources are distributed along a length of the amplifier waveguide to provide two or more amplification stages. ### Claim 34 (depends on 31) The laser source of claim 31, wherein a width of the amplifier waveguide adiabatically increases along a direction of propagation of the signal light. ### Claim 35 (depends on 31) The laser source of claim 31, wherein the amplifier waveguide is disposed at a common height above the substrate as at least one of the one or more pump sources. ### Claim 36 (depends on 35) The laser source of claim 35, wherein the pump light from the at least one of the one or more pump sources is coupled into the amplifier waveguide through one of the one or more cladding layers through a tapered waveguide. ### Claim 37 (depends on 31) The laser source of claim 31, wherein the invertible core comprises: a quantum well core including one or more quantum well layers, wherein the one or more quantum well layers provide quantum confinement of carriers along a single dimension. ### Claim 38 (depends on 37) The laser source of claim 37, wherein the quantum well core comprises: a multiple quantum well (MQW) core, wherein the one or more quantum well layers comprise two or more quantum well layers, wherein the two or more quantum well layers are separated by one or more barrier layers. ### Claim 39 (depends on 37) The laser source of claim 37, wherein the quantum well core comprises: a single quantum well core (SQW) formed as a single quantum well layer. ### Claim 40 (depends on 31) The laser source of claim 31, wherein the invertible core comprises: a bulk undoped semiconductor core. ### Claim 41 (depends on 31) The laser source of claim 31, wherein the signal source comprises: a laser diode. ### Claim 42 (depends on 31) The laser source of claim 31, wherein the amplified signal light has a power of at least 100 Watts.