A novel all-fiber magneto-optic switch based on high-speed magnetic field module

Abstract

All-fiber magneto-optic switch is presented in this paper which contains both of optical route and high-speed magnetic field module. The optical route has a 1×2 Fiber Polarization Beam Splitter (FPBS) and a 2×2 Dual Fiber Polarization Beam Splitter (DFPBS). The high-speed magnetic field module is core of all-fiber magneto-optic switch which changes the electronic pulse into magnetic pulse to control the light polarization's plane based on Faraday Effect. The high-speed magnetic field module adopts Yttrium Iron Garnet (YIG) crystal fiber, nanosecond impulser and high-speed magnetic field, characterized by no moving parts, low transmission loss and polarization insensitive, low optical insertion loss etc. YIG crystal fiber, the magneto-optic material with high Verdet constant, used to rotate the polarization plane of the polarized light 90° in all-fiber magneto-optic switch, is grown by Laser Heated Pedestal Growth (LHPG). CMOS chip FMMT415 which has good avalanche effect is employed to generate the nanosecond pulse. The pulse we measured is about 10 ns of the rising time and 0~600V of the amplitude and the output current is used to create the magnetic field. The obtained results indicate that the switch has a potential of low cross-talk, low insertion-loss and high switching speed. The optical route will be easily and quickly controlled by the means of nanosecond impulser, therefore, and the switching time is expected to less than 1 μs.