The LISA optical bench: an overview and engineering challenges

Abstract

This paper will present an overview of the LISA (Laser Interferometer Space Antenna) optical bench and discuss the innovative methods developed to analyse and mitigate significant engineering challenges. There are two optical benches for each of the three LISA spacecraft. The optical bench consists of numerous components which form the paths of the interferometers used to measure the displacement changes caused by gravitational waves. Given each spacecraft is separated by 2.5 million Km, a laser beam sent from one to another arrives with a significantly lower irradiance than on departure. It is in part because of this that various engineering challenges are faced by the LISA OB. This is alongside the extremely demanding nature of measuring gravitational waves at a sensitivity of pico-meters per root-Hertz.