Characterization of optical channel waveguides formed by FIB induced compositional mixing in AlGaAs MQWs

Abstract We have formed optical channel waveguides using focused ion beam (FIB) induced compositional mixing in an Al x Ga 1-x As multiple quantum well (MQW) structure. A focused Si ++ ion beam at 160 keV is implanted with a single scan of 5×10 14 cm -2 followed by rapid thermal annealing (RTA) at 950°C for 10 sec in order to achieve spatially selective compositional mixing. Raman microprobe spectra are used to characterize the lateral variation of compositional mixing transverse to the channel waveguides. Propagation loss of 4 μm and 8 μm wide channel waveguides are measured. Channel waveguide mode lateral intensity distributions are measured and used to determine the changes in effective refractive indices which are then used to estimate mixing depth.