FIBER OPTIC FREQUENCY SHIFTER

摘要

The fibre optic frequency shifters produce optical signals of a desired frequency range for input to a device such as an optical rotation sensing system. The rotating birefringence is created in a length of fibre optic material which has the effect of a rotating half-wave plate upon an input optical signal. The length of fibre optic material may have a jacket of either an electrostrictive of a magnetostrictive material such that appalication of an appropriate field to the jacket compresses the enclosed fibre to induce birefringence therein by means of the photoelastic effect.