Magneto-optic properties and sensing performance of garnet YbBi:YIG

A co-doped Bi-substituted rare-earth iron garnet single crystal YbBi:YIG was 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 -404 degrees cm(-1), magneto-optic figure of merit 25.8 degrees dB(-1), saturation magnetic field 1400 Oe, and temperature coefficient 4.2 x 10(-4) K-1 (at room temperature, lambda = 1.55 mum). It has larger Faraday rotation angle and magneto-optic figure of merit and lower temperature sensibility than pure YIG. A laboratory prototype sensor was established using the YbBi:YIG crystal as Faraday rotator element, and its sensing performance was tested under a 50 Hz factory frequency current. The tested results showed that the sensor system had high accuracy, sensitivity and good linearity. (C) 2001 Elsevier Science B.V. All rights reserved.