All-reflective interferometry for gravitational-wave detection

The circulating power within an interferometric gravitational-wave detector is limited by thermal lensing in transmissive optical elements [1]. All-reflective interferometers have been proposed to overcome this limitation [2,3]. In this paper we discuss the use of a low-efficiency diffraction grating as an input coupler for a high-finesse cavity. Residual thermal effects due to absorption in the high-reflection optical coatings are discussed.