Laser interferometry is used by gravitational wave detectors like LIGO. ... A laser interferometer measures the resulting distance by splitting a laser beam into two, sending each of the two beams along different directions in space (each along one of the two arms of the detector), and then recombining the beams.

What is the principle of interferometer?

Interferometry makes use of the principle of superposition to combine waves in a way that will cause the result of their combination to have some meaningful property that is diagnostic of the original state of the waves.

How does an interferometer measure things?

'Interferometry' is a measurement method using the phenomenon of interference of waves (usually light, radio or sound waves). ... By using two light beams (usually by splitting one beam into two), an interference pattern can be formed when these two beams superpose.