Diffractive Optics for Gravitational Wave Detectors

TL;DR

This paper explores the use of nano-structured diffraction gratings in all-reflective interferometers for gravitational wave detection, deriving input-output relations and testing a low-loss dielectric grating cavity.

Contribution

It introduces a novel all-reflective Fabry-Perot interferometer concept using 2nd order Littrow mount gratings, with derived relations and experimental testing.

Findings

Derived input-output relations for the grating-based resonator

Designed and tested a low-loss dielectric diffraction grating

Demonstrated the potential of diffractive optics in gravitational wave detectors

Abstract

All-reflective interferometry based on nano-structured diffraction gratings offers new possibilities for gravitational wave detection. We investigate an all-reflective Fabry-Perot interferometer concept in 2nd order Littrow mount. The input-output relations for such a resonator are derived treating the grating coupler by means of a scattering matrix formalism. A low loss dielectric reflection grating has been designed and manufactured to test the properties of such a grating cavity.