| CPC G02F 1/3548 (2021.01) [G02F 1/353 (2013.01); G02F 1/3534 (2013.01); G02F 1/3544 (2013.01); G02F 1/365 (2013.01); G02F 1/3775 (2013.01); H01S 3/0092 (2013.01); H01S 3/109 (2013.01); G02F 2201/305 (2013.01)] | 4 Claims | 

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               1. A method of forming a nonlinear wave mixing system with grating assisted phase matching, the method comprising: 
            determining a momentum of a backward grating needed to generate counter-propagating phase matching in produced light; and 
                forming the backward grating using the determined momentum of the backward grating in a nonlinear waveguide, the backward grating configured to diffract the produced light in a backward direction relative to a direction the produced light traveled in the nonlinear waveguide to reach the backward grating, the backward grating including at least one short period sidewall that provides a grating diffraction momentum that produces a phase matching condition. 
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