Measurement of semiconductor waveguide optical properties in the midinfrared wavelength range

We propose a technique based on Fabry-Perot fringes to analyze, in a broad wavelength range, the waveguide properties of semiconductor lasers in the midinfrared spectrum. This technique has been applied to strain-balanced Ga(0.32)In(0.68)As/Al(0.64)In(0.36)As quantum cascade lasers, with a double phonon active region, in order to determine propagation losses and the effective index between 2.5 and 8 mu m wavelength. These results are in good agreement with the values obtained using another method.