Bandwidth enhancement in difference frequency generation by domain-shifted quasi-phase-matching structure

Abstract

Bandwidth enhancement in difference frequency generation (DFG) has been investigated using domain-shifted quasi-phase-matching (QPM) structure of electrically poled ferroelectric crystals. The exact periodic QPM condition is relaxed by extending the periodic structure to a more flexible domain-shifted structure. The dependence of bandwidth enhancement and flatness on the positions and number of shifted domains are systematically studied for optimum output efficiency. The results presented here are useful for the fabrication of wide-bandwidth wavelength conversion devices based on the DFG process.