CHARACTERIZATION OF OPTICAL CHANNEL WAVE-GUIDES FORMED BY FIB INDUCEDCOMPOSITIONAL MIXING IN ALGAAS MQWS

We have formed optical channel waveguides using focused ion beam (FIB) induced compositional mixing in an AlxGa1-xAs multiple quantum well ( MQW) structure. A focused Si++ ion beam at 160 keV is implanted with a single scan of 5x10(14) cm(-2) followed by rapid thermal annealing (R TA) at 950 degrees C for 10 sec in order to achieve spatially selectiv e compositional mixing. Raman microprobe spectra are used to character ize the lateral variation of compositional mixing transverse to the ch annel waveguides. Propagation loss of 4 mu m and 8 mu m wide channel w aveguides are measured. Channel waveguide mode lateral intensity distr ibutions are measured and used to determine the changes in effective r efractive indices which are then used to estimate mixing depth.