Acousto-optic frequency shifter for single-mode fibres

Abstract

A fibre-optic frequency shifter has been constructed using a birefringent single-mode fibre positioned asymmetrically within two acoustic resonators driven 90° out of phase. The incident wave in one polarisation state is coupled to a frequency-shifted wave in the orthogonal state. Sideband suppression of better than 20 dB is achieved.