Quantum limits in interferometric detection of gravitational radiation

A spectral analysis is given of the quantum fluctuations in an optical interferometer to detect gravitational radiation. Two different methods of beating the standard quantum limit are examined: directing a squeezed state into the nonlaser input port of the interferometer and placing a Kerr medium into both arms of the interferometer. For both the Kerr medium and large squeezing cases the interferometer system is limited ultimately by the damping noise in the mirrors, not by noise in the light.