Generalized Snell-Descartes and Fresnel laws are derived for harmonic inhomogeneous plane waves that are incident upon a static interface between two continuous absorbing dielectric media that are macroscopically characterized by their electric and magnetic permittivities and their conductivities. A coordinate-free formalism based on complex vector algebra is used to carry out all discussions. Surprisingly, the usual complex Snell-Descartes laws for reflection and refraction and Fresnel laws for polarization are recovered only in the special case in which the vector characterizing the direction of inhomogeneity is in the plane of incidence. In the more general case a new deflection angle between planes of incidence and refraction has to be introduced. An experiment is proposed to test this prediction. A generalized form of the TE and TM modes (with respect to the interface), which are elliptically polarized and which are called parallel electric and parallel magnetic modes, also emerges.

Numerical simulations and experimental results are reported on bistable switching in a semiconductor nonlinear vertical Bragg reflector. An improved structure with an additional linear rear mirror and a phase-adjusting layer was predicted to have lower threshold for bistability than a Fabry–Perot type device. The experimental observation of bistable switching in a nonlinear Bragg reflector is reported. Achieved threshold was comparable with a nonlinear Fabry–Perot device; the simpler structure of a nonlinear Bragg device may represent an advantage with respect to growth tolerances.

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The optical nonlinearity of a GaAs/AlAs periodic layered structure was experimentally investigated for the first time. The shift of the reflectivity peak with increasing intensity was observed. A reflectivity contrast of about 10:1 was obtained by varying the incident intensity. Hysteresis loops due to the response delay of both the electronic and the thermal nonlinearity were observed. All-optical logic operations were also demonstrated. A further improvement of the structure may lead to a new type of optical bistable device.

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