Magneto-optic current sensors based on YbBi : YIG

A co-doped Bi-substituted rare earth iron garnet single crystal YbBi:YIG wa s grown from high temperature solution, and was used first time for magneto -optic optical fiber current sensors. The crystal has the specific Faraday rotation angle -404deg/cm, magneto-optic figure of merit 25.8deg/dB, satura tion magnetic field 1400Oe, and temperature coefficient 4.2 X 10(-4)K(-1) ( at room temperature, lambda = 1. 55 mum). It has larger Faraday rotation an gle and magneto-optic figure of merit and lower temperature sensibility tha n pure YIG. A laboratory prototype sensor was established using the YbBi:YI G crystal as Faraday rotator element, and its sensing performance was teste d under a 50Hz frequency AC. The tested results show that the sensor system has high accuracy, sensitivity and good linearity.