# US 9,753,353 B2 · System and method for optical signal quadrature separation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,753,353 B2 - Document ID: US9753353B2 - Status: Granted - Kind: B2 - Application number: 15/166,883 - Filed: 2016-05-27 - Published: 2016-12-08 - Granted: 2017-09-05 - Earliest claimed: 2015-06-03 - Assignees: Vencore Labs, Inc. - Applicants: Vencore Labs, Inc. - Inventors: Colin McKinstrie; Anjali Agarwal - Web page: https://patentgrep.com/patent/US9753353B2 ## CPC - G02F 1/39: for parametric generation or amplification of light, infrared or ultraviolet waves - G02F 1/3532: {Arrangements of plural nonlinear devices for generating multi-colour light beams, e.g. arrangements of SHG, SFG, OPO devices for generating RGB light beams} - H01S 3/0078: {Frequency filtering} - G02F 1/392: {Parametric amplification} - G02F 2203/13: involving THZ radiation - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS - 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 system and method for separating signal quadratures includes obtaining, by a parametric amplifier, an input signal, amplifying, by the parametric amplifier, the input signal to create an amplified signal and generating an idler. The idler is a conjugate image of the input signal. The system and method also include obtaining, by a frequency converter, the amplified signal and the conjugate image and converting the amplified signal and the conjugate image into a first output and a second output, where the first output includes a first signal quadrature and the second output includes a second output quadrature. ## Claims ### Claim 1 A method for separating signal quadratures comprising: obtaining, by a parametric amplifier, an input signal; amplifying, by the parametric amplifier, the input signal to create an amplified signal, generating, by the parametric amplifier, an idler comprising a conjugate image of the input signal; obtaining, by a pump filter, from the parametric amplifier, the amplified signal and the conjugate image; filtering out, by the pump filter, an optical pump from the amplified signal and the conjugate image; supplying, by the pump filter, the amplified signal and the conjugate image to a frequency converter; and obtaining, by the frequency converter, the amplified signal and the conjugate image, and converting the amplified signal and the conjugate image into a first output and a second output, wherein the first output comprises a first output signal quadrature and the second output comprises a second output signal quadrature. ### Claim 2 (depends on 1) The method of claim 1, where the amplifying comprises copying the input signal onto another wavelength. ### Claim 3 (depends on 1) The method of claim 1, wherein the first output signal quadrature is a real part of the input signal and the second output signal quadrature is an imaginary part of the input signal. ### Claim 4 (depends on 1) The method of claim 1, wherein the parametric amplifier is a chi(3) phase-insensitive amplifier. ### Claim 5 (depends on 1) The method of claim 1, wherein the frequency converter is a chi(3) frequency convertor operating with a conversion efficiency of about 50%. ### Claim 6 (depends on 1) The method of claim 1, wherein the first output comprises an output signal carrying a real quadrature of the input signal, and wherein the second output comprises an output idler carrying an imaginary quadrature of the input signal. ### Claim 7 (depends on 1) The method of claim 1, the method further comprising: before the obtaining, upconverting a terahertz (THz) signal to an optical signal and an optical idler, wherein the optical signal and the optical idler comprise the input signal. ### Claim 8 (depends on 1) The method of claim 1, wherein the parametric amplifier comprises an optical pump and in the parametric amplifier, a sum of pump phases equals a signal phase and an idler phase. ### Claim 9 (depends on 1) The method of claim 1, wherein the frequency converter comprises an optical pump and a difference between pump phases equals a difference between a signal phase and an idler phase. ### Claim 10 A system for separating signal quadratures comprising: a parametric amplifier to obtain an input signal and to amplify the input signal to generate an amplified signal and an idler comprising a conjugate image of the input signal; a frequency converter, coupled to the parametric amplifier, to obtain the amplified signal and the conjugate image from the parametric amplifier and to convert the amplified signal and the conjugate image into a first output and a second output, wherein the first output comprises a first signal quadrature and the second output comprises a second signal quadrature; and a pump filter, coupled to the parametric amplifier and the frequency converter, to obtain the amplified signal and the conjugate image from the parametric amplifier, to filter an optical pump from the amplifier signal and the conjugate image, and to supply the amplified signal and the conjugate image to the frequency converter. ### Claim 11 (depends on 10) The system of claim 10, wherein the parametric amplifier and the frequency converter comprise optical pumps. ### Claim 12 (depends on 10) The system of claim 10, wherein the parametric amplifier is a chi(3) phase-insensitive amplifier. ### Claim 13 (depends on 12) The system of claim 12, wherein the parametric amplifier and the frequency converter comprise optical pumps. ### Claim 14 (depends on 10) The system of claim 10, wherein the frequency converter is a chi(3) frequency convertor operating with a conversion efficiency of about 50%. ### Claim 15 (depends on 10) The system of claim 10, wherein the parametric amplifier is degenerate. ### Claim 16 (depends on 10) The system of claim 10, wherein the parametric amplifier is nondegenerate. ### Claim 17 (depends on 10) The system of claim 10, wherein the parametric amplifier comprises an optical pump and in the parametric amplifier, a sum of pump phases equals a signal phase and an idler phase. ### Claim 18 (depends on 10) The system of claim 10, wherein the frequency converter comprises an optical pump and a difference between pump phases equals a difference between a signal phase and an idler phase.