400 MHZ-BANDWIDTH ALL-FIBER PHASE MODULATORS WITH ZNO COATING ON STANDARD TELECOMMUNICATION FIBER

Miniature all-fiber phase modulators with a radially symmetrical piezo electric ZnO jacket have been characterized over a wide frequency rang e up to 1 GHz, Multiple radial resonances with phase shift values as h igh as 0.82 rad were observed in the frequency region between 20-400 M Hz, A linear dependence of the phase shift on the square root of the d riving power is observed up to 125 mW with a phase shift efficiency of 0.21 and 0.175 rad/root mW per centimeter fiber length at 196.5 and 3 99.5 MHz, respectively, The dependence of the phase shift efficiency o n the modulation length is demonstrated.