Optical channel waveguides in AlGaAs multiple-quantum-well structures formed by focused ion-beam-induced compositional mixing

Optical channel waveguiding in a AlGaAs multiple-quantum-well structure was demonstrated in a channel formed by compositional mixing induced by focused ion beam (FIB) implantation. Selective mixing was achieved by FIB implanting Si/sup ++/ with a dose of 5*10/sup 14/ cm/sup -2/ followed by rapid thermal annealing at 950 degrees C for 10 s. Raman microprobe spectra were used to characterize the lateral variation of compositional mixing. Channel waveguide loss of 17.2 dB/cm was measured, compared to 10-12 dB/cm measured for planar waveguiding. Mode field pattern measurements indicate that a change in effective index of 2.7*10/sup -4/ was induced, corresponding to an approximate mixing depth of 270 nm.<
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