2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/34654Electromagnetic methods recently proposed for detecting gravitational waves modify the Michelson phase shift analysis (historically employed for special relativity). We suggest that a frequency modulation analysis is more suited to general relativity. An incident photon in the presence of a very long wavelength gravitational wave will have a finite probability of being returned as a final photon with a frequency shift whose magnitude is equal to the gravitational wave frequency. The effect is due to the non-linear coupling between electromagnetic and gravitational waves. The frequency modulation is derived directly from the Maxwell-Einstein equations.4 pages, 3 *.eps figures, RevTeX 4 formatGeneral Relativity and Quantum Cosmologytext