Optical sum-frequency generation in whispering gallery mode resonators

TL;DR

This paper demonstrates efficient sum-frequency generation in a whispering gallery mode resonator, enabling enhanced optical conversion for quantum networking and information processing applications.

Contribution

It introduces a novel implementation of sum-frequency generation in a nonlinear whispering gallery mode resonator with natural phase matching and ultra high Q, achieving significant efficiency enhancement.

Findings

1000-fold increase in conversion efficiency over waveguide devices

Agreement between experimental data and nonlinear dynamics theory

Potential for quantum networking and optical signal manipulation

Abstract

We demonstrate sum-frequency generation in a nonlinear whispering gallery mode resonator between a telecom wavelength and the Rb D2 line, achieved through natural phase matching. Due to the strong optical field confinement and ultra high Q of the cavity, we achieve a 1000-fold enhancement in the conversion efficiency compared to existing waveguide-based devices. The experimental data are in agreement with the nonlinear dynamics and phase matching theory in the spherical geometry employed. The experimental and theoretical results point to a new platform to manipulate the color and quantum states of light waves toward applications such as atomic memory based quantum networking and logic operations with optical signals.