Noncritical phasematching behavior in thin-film lithium niobate frequency converters

We present a study of noncritical phasematching behavior in thin-film, periodically poled lithium niobate (PPLN) waveguides. Noncritical phasematching refers to designing waveguides so that the phasematching is insensitive to variations inwaveguide thickness, width, or other parameters. For waveguide thickness (the dimension with greatest nonuniformity due to fabrication), we found that phasematching sensitivity can be minimized but not eliminated. We estimate limits on the acceptable thickness variation and discuss scaling with device length for second-harmonic generation and sum-frequency generation in thin-film PPLN frequency converters.

Automated summary

This study investigates the noncritical phasematching behavior in thin-film, periodically poled lithium niobate (PPLN) waveguides. It is found that although the sensitivity of phasematching to waveguide thickness can be minimized, it cannot be completely eliminated. Limits on acceptable thickness variation are estimated, and the scaling with device length for second-harmonic generation and sum-frequency generation in thin-film PPLN frequency converters is discussed.