All-reflective Michelson, Sagnac, and Fabry–Perot interferometers based on grating beam splitters

Abstract

All-reflective Michelson, Sagnac, and Fabry-Perot interferometers based on grating beam splitters are experimentally demonstrated at a wavelength of 1064 nm. A 1200-groove/mm grating diffracting 0 and -1 orders with an efficiency of 48.2% for each order was used as a near-50/50 beam splitter. The all-reflective Sagnac and Michelson interferometers were formed by reintroducing both of the diffracted beams back to the grating. The Fabry-Perot interferometer was formed in a Littrow configuration by using a 1700-groove/mm grating with a blazing efficiency of 91% as a cavity coupler. These interferometers encompass all the fundamental configurations of all-reflective laser interferometric gravitational-wave detectors, promising improved wave-front quality by avoiding volume thermal effects in transmissive optics under high-power laser illumination.

Development of Mirror Coatings for Gravitational Wave Detectors

“…These include diffractively-coupled mirrors [81,82], the use of corner reflectors [83], or the use of waveguide (macro-structured) surfaces [84,85]. These coating-free solutions still require significant development.…”

Lateral input-optic displacement in a diffractive Fabry-Perot cavity

“…The sensitivity of proposed gravitational wave detectors utilising the laser-interferometric technique might be improved by reducing the number of transmissive optical components and at the extreme adopting an all-reflective optical configuration [1]. Particular focus falls on the beam-splitter and cavity input mirrors of a Michelson interferometer with Fabry-Perot arm cavities as are used in LIGO [2] and Virgo [3] and which will be used for the upgrades to those detectors.…”

Experimental demonstration of a suspended diffractively coupled optical cavity

“…Several proof-of-principle [4] and bench-top [5] experiments have been carried out to demonstrate the principles of operation for diffractive couplers in optical cavities. To examine the applicability of such systems to suspended instruments, one of the arm cavities of the Glasgow 10 m prototype interferometer was commissioned as a diffractively coupled optical cavity (see Fig.…”