Low-loss grating for coupling to a high-finesse cavity

TL;DR

This paper demonstrates a low-loss all-reflective cavity coupler using a dielectric reflection grating at 1064 nm, achieving a finesse of 400, with potential applications in gravitational-wave detectors.

Contribution

It introduces a novel low-loss reflective cavity coupler based on a dielectric grating, suitable for high-finesse optical cavities.

Findings

Achieved a finesse of 400 with the grating coupler.

Used a 1450 nm period dielectric reflection grating with 0.58% diffraction efficiency.

Discussed potential applications in gravitational-wave detectors.

Abstract

A concept for a low loss all-reflective cavity coupler is experimentally demonstrated at a wavelength of 1064 nm. A 1450 nm period dielectric reflection grating with a diffraction efficiency of 0.58 % in the -1st order is used in 2nd order Littrow configuration as a coupler to form a cavity with a finesse of 400. The application of such reflective low-loss cavity couplers in future generations of gravitational-wave detectors as well as some implementation issues are discussed.