FARADAY-STARK OPTOELECTRONIC EFFECT

An optoelectronic effect based on Faraday or Kerr rotation and the qua ntum-confined Stark shift is demonstrated. It is novel in that the deg ree of rotation is controlled by an electric field as opposed to a mag netic field. By applying an electric field to a quantum well structure , the Faraday rotation can be tuned into resonance, thereby varying th e rotation angle of plane polarized light. We have observed a resonant rotation of 10 degrees in GaAs at a magnetic field of 1 T. By applyin g a gate voltage of 2 V to a GaAs/AlGaAs superlattice structure, we ob served a change in rotation of 1.3 degrees at 2 K. The Faraday-Stark e ffect could be useful in electrically controlled light switches and hi gh-speed optical modulators. (C) 1996 American Institute of Physics.