The gravito-optic effect

Abstract: Gravitational waves have predominantly been detected using interferometric techniques, with standard approaches limited to 10 kHz and with modern advancements extending this bound to 300 kHz. To explore the largely uncharted higher-frequency gravitational wave spectrum, a general wave optics formalism is presented here, revealing a space-time-periodic correction to the electromagnetic wave equation, along with the emergence of sidebands at characteristic angles in the presence of an incident gravitational wave (analogous to acousto-optic diffraction). Then a Fabry-P\'erot-enhanced heterodyne detection scheme is proposed to amplify and measure this effect. It is demonstrated that such a detection strategy has the potential of extending gravitational wave detection to high-frequency regimes far beyond the LIGO sensitivity band. This novel approach provides a pathway to probing new physics through high-frequency gravitational waves in the MHz-GHz range.