8.7 Interferometer
An interferometer is an optical tool used in detecting gravitational waves. It is a very sensitive detection device that may use the interference of LASER (Light Amplification by Stimulated Emission of Radiation) beams. The basic LIGO interferometer can be seen in Fig. 8.9.
An interferometer that detects gravitational waves is a highly sensitive instrument that uses LASER light to measure tiny changes in distance between mirrors, caused by gravitational waves passing through the detectors. These interferometers are called LIGO (LASER Interferometer Gravitational Wave Observatory).
The main differences between LIGO and conventional interferometers are:
(a) LIGO is times larger than conventional device, and (b) LIGO uses LASER whereas conventional interferometer has normal light source.