Optical parametric interactions in isotropic materials using a phase-corrected stack of nonlinear dielectric plates

Abstract

Optical parametric interactions are analyzed for collinear three‐frequency processes in a series of plates of isotropic nonlinear dielectric. Phase‐velocity mismatch caused by refractive‐index dispersion is compensated by making each plate one coherence length thick and orienting consecutive plates so the nonlinear polarization is shifted in phase by π. Parametric transfer of energy then proceeds constructively along the axis of propagation. For second harmonic generation, frequency upconversion and downconversion, and parametric amplification the output intensity is proportional to the square of the number of phase‐corrected plates. The conversion efficiency is the same as for a hypothetical phase‐velocity‐matched interaction in the same nonlinear material, except that the nonlinear susceptibility is effectively reduced by a factor of 2/π.This method can be used to obtain efficient nonlinear interactions over frequency ranges previously precluded by lack of suitable transparent birefringent crystals and for large‐aperture configurations for generating high powers.