Gravitational wave interferometry: how does it work?

摘要

Abstract: The existence of gravitational waves is predicted by the general relativity theory, but they have not yet been measured directly. The difficulty with these measurements is the very small signals expected from even the strongest sources (astrophysical events such as supernovae). Detection of gravitational waves by interferometric detectors requires resolution of very small displacements, which in turn requires very long arm lengths. In the case of the Laser Interferometer Gravitational-Wave Observatory (LIGO), Michelson interferometers with arm lengths of 4 km and position accuracy on the order of 10$+$MIN@18$/ meters are to be employed. LIGO, funded by the US National Science Foundation, is being constructed at two sites in the United States with initial observation planned in 2002. An overview of the LIGO design requirements, configuration, and control scheme is presented. The optical configuration is discussed in general with particular attention to the characteristics of the core optics. In addition, a brief overview of large- scale gravitational wave observation projects worldwide is presented.!9