  Sagnac effect has been studied in terms of Gyroscopic system in both Lorentz
frame as well as flat Einstein frame. The Einstein equivalence principle has
been used to determine the phase shift due to pseudo force in the
transformation from rotating earth frame to stationary frame. A polychromatic
broadband source has been considered for the discussion. The
Langevin-Landau-Lifschitz metric has been used during the incorporation of
General theory of relativity. The square type sagnac interferometer has been
used in theory establishment.
