Integrated fiber Mach-Zehnder interferometer for electro-optic switching

Molten alloys under high pressure were used to obtain fibers with long internal electrodes that are solid at room temperature. An integrated Mach-Zehnder interferometer was constructed from a twin-core twin-hole fiber that permitted application of an electric field preferentially to one of the cores. Good stability and a switching voltage of 1.4kV were measured with a 1-m-long fiber device with a quadratic voltage dependence.