Polarisation dependent all-optical nonlinearity far from the bandedge in active GaAs/AlGaAs quantum well waveguides

The authors report a very strongly polarisation dependent nonlinearity of 1.06 mu m, and, using a model of a nonlinear Fabry-Perot waveguide cavity, an effective value of the nonlinear refractive index has been deduced to be -3*10/sup -15/ and -4*10/sup -6/ m/sup 2//W for TM and TE polarised light respectively. Various nonlinear processes have been considered for the nonlinear refraction. A measurement of the two photon absorption coefficient in the cavity using input optical power levels of less than a watt peak is described.<
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