MULTIPLE-QUANTUM-WELL NONLINEAR WAVE-GUIDE GRATING DEVICE

We report on the preliminary experimental demonstration of a multiple-quantum-well waveguide grating element. Due to optical nonlinearities in a multiple-quantum-well layer incorporated into the structure, the out-coupling angle of the grating is varied by the intensity of light in a guided mode. Experiments with GaAs-based planar as well as rib waveguide samples confirmed theoretical predictions. Changes in the coupling angle obtained are on the order of minutes. The demonstrated principle can be employed in fine tuning of the coupling angle, fine focusing of the output beam, or as a nonlinear beam-steering method for dispersion measurements.