High-Frequency Gravitational Wave Detection via Optical Frequency Modulation

High frequency gravitational waves can be detected by observing the frequency modulation they impart on photons. We discuss fundamental limitations to this method related to the fact that it is impossible to construct a perfectly rigid detector. We then propose several novel methods to search for <math display="inline"><mrow><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><mrow><mi>MHz</mi></mrow><mo>-</mo><mrow><mi>GHz</mi></mrow><mo stretchy="false">)</mo></mrow></math> gravitational waves based on the frequency modulation induced in the spectrum of an intense laser beam, by applying optical frequency demodulation techniques, or by using optical atomic clock technology. We find promising sensitivities across a broad frequency range.