Revisiting the Fresnel-phase-matched nonlinear frequency conversion

Abstract

A flexible phase-matching method is introduced to manipulate the energy flow in nonlinear frequency conversion processes. With the use of photonic crystal as the reflective medium, the phase mismatching could be adjusted by the interface and the nonlinear crystal. We call this method the reflective phase matching. Here we present an experiment to demonstrate this idea in a single-domain MgO:CLN wafer with photonic crystal on the surface. A frequency-doubling signal enhanced 52 times is achieved. The result suggests the potential of the function to one more dimension phase matching without additional artificial structure inside the crystal. In addition, the proposed reflective phase-matching method could find broad application in the nonlinear optics and laser device miniaturization and integration.