Question

Does shortening the path length of an excited etalon do work? What about LIGO?

Answer 1

LIGO is the world's largest gravitational wave observatory and a cutting edge physics experiment. Comprising two enormous laser interferometers located thousands of kilometers apart, LIGO exploits the physical properties of light and of space itself to detect and understand the origins of gravitational waves.

Answer 2

Explanation:

yes shortening the path length of an excited etalon do work.