QUANTUM-WELL INTERMIXING FOR THE CONTROL OF 2ND-ORDER NONLINEAR EFFECTS IN ALGAAS MULTIPLE-QUANTUM-WELL WAVE-GUIDES

We present experimental evidence to demonstrate the feasibility of a p romising new quasi-phase-matching technique in AlGaAs multiple-quantum -well waveguides. Non-phase-matched second-harmonic-generation measure ments indicate that, for sub-half-bandgap excitation near 1.5 mu m, qu antum-well intermixing by impurity-free vacancy disordering results in a reduction of the nonlinear susceptibility chi(zxy)((2)) (similar to 340 pm/V) by 17%. Relatively low intermixed waveguide losses, and the high spatial resolution of the impurity-free vacancy disordering proc ess, suggest that periodic intermixing along the direction of propagat ion should lead to useful frequency-conversion efficiencies. (C) 1997 Optical Society of America.