Optical parametric amplification and oscillation assisted by low-frequency stimulated emission

TL;DR

This paper proposes a novel method for up-conversion optical parametric amplification and oscillation using stimulated emission, enabling coherent light generation at higher frequencies than the pump, demonstrated with Nd-doped PPLN crystals.

Contribution

It introduces a new approach for up-conversion parametric processes assisted by stimulated emission, expanding the capabilities of nonlinear optical devices.

Findings

Design parameters for up-conversion oscillation at 465 nm are provided.

The method enables amplification of higher-frequency signals with a lower-frequency pump.

Potential for coherent light generation in spectral regions inaccessible to traditional lasers.

Abstract

Optical parametric amplification/oscillation provide a powerful tool for coherent light generation in spectral regions inaccessible to lasers. Parametric gain is based on a frequency {\it down-conversion} process, and thus it can not be realized for signal waves at a frequency $\omega_3$ {\it higher} than the frequency of the pump wave $\omega_1$. In this work we suggest a route toward the realization of {\it up-conversion} optical parametric amplification and oscillation, i.e. amplification of the signal wave by a coherent pump wave of lower frequency, assisted by stimulated emission of the auxiliary idler wave. When the signal field is resonated in an optical cavity, parametric oscillation is obtained. Design parameters for the observation of up-conversion optical parametric oscillation at $\lambda_3=465$ nm are given for a periodically-poled lithium-niobate (PPLN) crystal doped with Nd$^{3+}$ ions.