Magneto-Optical Properties of Bi-Substituted Magnetic Garnets and Their Application to a Long Wavelength Optical Isolator

GdBiIG Faraday rotator magneto-optical characteristics measurements showed that the 1.3 ¿m linear polarized light transmitted through a Faraday rotator coated with a nonreflective coating decreases at extinction, but increases at transmission as the applied magnetic field increases. Using this and other results, the authors constructed a 1.3 ¿m optical isolator using a GdBiIG Faraday rotator. Calcite birefringent plates were used for the polarizer and the analyzer. A cylindrical permanent magnet was included to bring the Faraday rotator to saturation magnetization. The GdBiIG Faraday rotator loss was 0.04 dB, and the combined loss for the polarizer and the analyzer was 0.05 dB, for a total loss of 0.09 dB; an extremely low value. The level of 1.3 ¿m linear polarized light transmitted through the Faraday rotator coated with a nonreflective coating was measured by rotating the analyzer.