Phase-Matching in Nonlinear Optical Compounds: A Materials Perspective

Abstract

Angle phase-matching in nonlinear optical (NLO) materials is critical for technological applications. The purpose of this manuscript is to describe the concept of phase-matching for the materials synthesis NLO community. Refractive index and birefringence are defined with respect to uniaxial and biaxial crystal systems. The phase-matching angle and wavelength range, Type I and Type II, are explained using real NLO materials, K3B6O10Cl (KBOC) and Ba3(ZnB5O10)PO4 (BZBP) In addition, we describe how refractive index measurements are performed on single crystals and how the resulting birefringence impacts the phase-matching. Our goal is to provide a description of phase-matching that is relevant for the materials synthesis NLO community.