Faraday rotation in an InP waveguide

Waveguide Faraday rotation was demonstrated in an InP waveguide with magnetic dopants. The modal Verdet coefficient was 10 S/mm T at a wavelength of 1.55 mu m. It was found that the Verdet coefficient of the Fe: In1-xGaxAsyP1-y (x=0.290, y=0.628) core was 12.5 S/mm T at a wavelength of 1.55 mu m. The Verdet coefficient dependence on wavelength is in agreement with theory. The loss of the waveguide was 4.34 dB/cm, giving a magneto-optic figure of merit of 23 at a magnetic field of 1 T and a wavelength of 1.55 mu m. This semiconductor waveguide shows promise for monolithically integrated optical isolators. (c) 2007 American Institute of Physics.