A bistable etalon, consisting of an optically nonlinear semiconductor spacer layer sandwiched between two Bragg mirrors, has been optimized for use in reflection, using a numerical model for a self-consistent carrier density based on published experimental data for the nonlinear absorption alpha(I,lambda) and refraction DELTA-n(I,lambda). The saturation behavior of the refractive index and the absorption in bulk GaAs has been investigated at different wavelengths. High saturation values of DELTA-n(s) almost-equal-to .080 were found 20 meV below the gap. 30 meV above the gap we observed a comparable index change, together with an absorption saturation feature, leading to a highly nonlinear response close to the bistability threshold in our unoptimized etalon.
Andreas Mortensen, Yves Bellouard, Jérôme Faist, Gözden Torun, Enrico Casamenti, Luciano Borasi, Mathieu Bertrand
Giovanni De Cesare, Azin Amini, Stéphanie Joëlle André, Jean-Noël Saugy