Photo-induced cascaded harmonic and comb generation in silicon nitride microresonators.

ABSTRACT: Silicon nitride (Si₃N₄) is an ever-maturing integrated platform for nonlinear optics but mostly considered for third-order [χ⁽³⁾] nonlinear interactions. Recently, second-order [χ⁽²⁾] nonlinearity was introduced into Si₃N₄ via the photogalvanic effect, resulting in the inscription of quasi-phase-matched χ⁽²⁾ gratings. However, the full potential of the photogalvanic effect in microresonators remains largely unexplored for cascaded effects. Here, we report combined χ⁽²⁾ and χ⁽³⁾ nonlinear effects in a normal dispersion Si₃N₄ microresonator. We demonstrate that the photo-induced χ⁽²⁾ grating also provides phase-matching for the sum-frequency generation process,

SUBMITTER: Hu J 

PROVIDER: S-EPMC9750138 | biostudies-literature | 2022 Dec

REPOSITORIES: biostudies-literature