Squeezed state enhanced two frequency interferometry.

Here an experiment is proposed to demonstrate squeezed state enhanced interferometry. An interferometer employing differenced detection, in which the photodetectors have a less than unit quantum efficiency, is analyzed. In order to avoid low frequency noise, a readout signal at frequency 2 nu sub s is generated at the detector by injecting coherent light having two frequency components nu sub o + nu sub s and nu sub o - nu sub s into one input port of the interferometer. In order to realize a significant sensitivity enhancement, squeezed light fed into the other input port must be squeezed at frequencies nu sub o +- nu sub s and nu sub o +- 3 nu sub s.