Abstract

A novel type of fiber-optic electric field sensor has been demonstrated. This device was fabricated by fusing piezoelectrically sensitized fibers into a fiber-optic Mach-Zehnder interferometer testbed. Quadrature stabilization for the interferometer test-bed was provided by an active homodyne scheme. The fibers were sensitized to an electric field by embedding them in a piezoelectric material that expands and contracts in response to the electric field. The resulting pressure waves modulate the optical path length through the sensitized fiber, which modulates the output of the fiber-optic interferometer. Two designs were used to sensitize fibers to electric fields. In the first design, unjacketed fibers were embedded in a piezoelectric lithium borosilicate (LBS) glass plate. In the second design, fibers were embedded in a composite PZT material. One of the LBS sensitized fibers and three of the PZT sensitized fibers were tested in the fiber-optic interferometer test-bed. The signal to noise of each sensor was mapped out vs frequency, with a reference electric field applied across the sensors. Future efforts will be devoted to directly coating an unjacketed fiber with a thin LBS coating.

© 1986 Optical Society of America