Method of adjusting thermal dependence of the refractive index of an optical fiber

A method of adjusting the thermal dependence of the refractive index of an optical fiber is demonstrated. The method involves using a photosensitive fiber as one arm of an all-fiber Mach-Zehnder interferometer. Before the MZI fabrication process, the fiber is exposed to UV radiation so as to adjust the thermal dependence of the interferometer transmission peaks. The time of exposition to UV radiation allows changing the transmission peaks shift from −16 to +20 pm/°C.