摘要: The photon motion in a Michelson interferometer is re-analyzed in both
geometrical optics and wave optics. The classical paths of the photons in the
background of gravitational wave are derived from Fermat principle, which is the same
as the null geodesics in general relativity. The deformed Maxwell equations and the
wave equations of electric elds in the background of gravitational wave are presented
in
at-space approximation. Both methods show that the response of an interferometer
depends on the frequency of a gravitational wave, however it is almost independent of
the frequency of the mirror's vibrations. It implies that the vibrating mirror cannot
mimic a gravitational wave very well.