An Electro-Optical Frequency Shifter

A proposed electro-optical apparatus would shift the frequency of a laser beam by a controllable amount within the range of about ±10 GHz. It would be a wide-band alternative to an acousto-optical tunable filter, which is limited to a frequency shift of about 100 kHz. The power efficiency of the proposed apparatus would be nearly 100 percent; the main insertion loss would be only about 2 dB and would be associated with fiber-optic input and output.