High-efficiency all-fiber phase modulator using an annular zinc oxide piezoelectric transducer

We present a high-efficiency in-fiber phase modulator, which consists of an annular ZnO piezoelectric transducer deposited on a gold-coated optical fiber by reactive RF planar magnetron sputtering. The deposited film is highly oriented and uniform in thickness and structure, which results in highly efficient acoustooptic interaction in the fiber core. Experimental results show modulator performance significantly exceeding previously reported devices.