Bichromatic local oscillator for detection of two-mode squeezed states of light

We present a new technique for the detection of two-mode squeezed states of light that allows for a simple characterization of these quantum states even for arbitrary frequency separation between the modes. The proposed technique is based on the use of a bichromatic field as the local oscillator in a balanced heterodyne measurement scheme. By the proper selection of the frequencies of the bichromatic field, it is possible to arbitrarily select the frequency around which the squeezing information is located, thus making it possible to use a low-bandwidth detection system and to move away from any excess noise present in the system.