Frequency tuning of a squeezed vacuum state using interferometric enhanced Bragg diffraction effect

We experimentally demonstrate a high frequency tuning scheme for the squeezed vacuum state by using acoustooptic modulator based on bi-frequency interferometer. The tuning frequency is determined by the acousto-optic modulator’s driving frequency, which is 80 MHz, at least 3 orders of magnitude larger than the line-width of the laser used for state generation. The efficiency of the frequency tuning device is 91%, limited only by the transmittance of the acousto-optic modulators.