Nonlinear measurement of mid-infrared absorption in AlOx waveguides

Abstract

We report a quantitative study on the absorption of oxidized-AlAs (AlOx) integrated thin layers in the mid-infrared range (2–4μm). An AlOx absorption coefficient of 1600cm−1 is measured in a nonlinear waveguide, by investigating the phase-matching bandwidth of parametric fluorescence. Since mid-infrared optical losses of the idler mode are inferred from the corresponding signal features in the 1–2μm range, our technique takes advantage of common near-infrared sources and detectors.