Efficient 525nm laser generation in single or double resonant cavity

TL;DR

This study demonstrates highly efficient sum frequency generation to produce 525 nm laser light using single and double resonant cavities with PPKTP, achieving high power and conversion efficiency, useful for quantum optics applications.

Contribution

The paper introduces optimized cavity configurations for efficient sum frequency generation at 525 nm, with significantly improved conversion efficiencies over previous methods.

Findings

Maximum power of 373 mW at 525 nm with double resonant cavity.

Quantum conversion efficiency of 77% in double resonant configuration.

Intra-cavity single pass conversion efficiency around 5%.

Abstract

This paper reports the results of a study into highly efficient sum frequency generation from 792 and 1556 nm wavelength light to 525 nm wavelength light using either a single or double resonant ring cavity based on a periodically poled potassium titanyl phosphate crystal (PPKTP). By optimizing the cavity$'$s parameters, the maximum power achieved for the resultant 525 nm laser was 263 and 373 mW for the single and double resonant cavity, respectively. The corresponding quantum conversion efficiencies were 8 and 77\% for converting 1556 nm photons to 525 nm photons with the single and double resonant cavity, respectively. The measured intra-cavity single pass conversion efficiency for both configurations was about 5\%. The performances of the sum frequency generation in these two configurations were studied and compared in detail. This work will provide guidelines for optimizing the generation of sum frequency generated laser light for a variety of configurations. The high conversion efficiency achieved in this work will help pave the way for frequency up-conversion of non-classical quantum states, such as the squeezed vacuum and single photon states. The proposed green laser source will be used in our future experiments, which includes a plan to generate two-colour entangled photon pairs and achieve the frequency down-conversion of single photons carrying orbital angular momentum.