Dynamics of a Fabry–Perot cavity in the field of a plane gravitational wave

The interaction of a weak gravitational wave with a Fabry–Perot cavity is analysed beyond the long-wavelength approximation in the input-mirror locally Lorentzian frame of reference taking the light pressure into account. The generalised expressions are obtained for the coefficient of pondermotive optical rigidity, the motion law of the moving mirror of the cavity and the response function of the cavity. It is shown that the latter is a sum of two phase shifts of a circulating light wave: the phase incursion after reflection from the moving mirror and the phase incursion due to the direct interaction of gravitational and light waves in the cavity. The possibility of the resonance detection of high-frequency gravitational waves by using the optical rigidity effect is considered.