We report the inscription of quasi-phase-matching gratings in silicon nitride waveguides for backward second-harmonic-generation enabled by all-optical poling, therefore, circumventing the difficulties in inscribing poled domains with ultra-short periods.
Camille Sophie Brès, Anton Stroganov, Boris Zabelich, Christian André Clément Lafforgue, Edgars Nitiss
Kirsten Emilie Moselund, Chang Won Lee