Registration of Relic Gravitational Waves using Low-Frequency Optical Resonance

Abstract

The study centers around the possible existence of high-frequency relic gravitational waves, focuses on specialized gravitational antennas necessary for their registration, and proposes to use low-frequency optical resonance laser gravitational antennas. Within the study, we calculated the sensitivity of the Fabry --- Perot interferometer, which uses the phenomenon of low-frequency optical resonance, and obtained formulasto describe the radiation transmitted by the Fabry --- Perot interferometer and the spectral density of the response to the action of a gravitational wave. The study reveals the possibility of registering relic gravitational waves in the high-frequency part of the spectrum, and estimates the limiting sensitivity of a laser gravitational antenna. Findings of the research show that the main factor limiting the sensitivity of a laser gravitational antenna is photon noise. To reduce the contribution of photon noise, we propose to significantly reduce the power of laser radiation transmitted through the Fabry --- Perot interferometer, which can be achieved using low-frequency optical resonance. We estimated the required power of the radiation transmitted through the interferometer to achieve the limiting sensitivity of the laser gravitational antenna. The mathematical modeling confirmed the presence of low-frequency optical resonance in the high-frequency part of the radiation spectrum that passed through the Fabry --- Perot interferometer. We found that in the high-frequency region the resonant response exceeded by 2 orders of magnitude the non-resonant effect on the Fabry --- Perot interferometer