Optical properties of asymmetrical multiple quantum wells for the construction of quantum cascade lasers are calculated, and expressions for the electronic states of asymmetrical multiple quantum wells are presented. The gain and differential cross-section for an electron Raman scattering process are obtained. Also, the emission spectra for several scattering configurations are discussed, and the corresponding selection rules for the processes involved are studied; an interpretation of the singularities found in the spectra is given. The electron Raman scattering studied here can be used to provide direct information about the efficiency of the lasers.

The differential cross section for an electron Raman scattering process in a semiconductor quantum well wire (QWW) and in a free-standing wire of cylindrical geometry involving phonon-assisted transitions is calculated for T = 0 K. A complete description of the phonon modes of cylindrical structures embedded in another material, including a correct treatment of the mechanical and electrostatic matching conditions at the surface, is presented. We consider the Fröhlich interaction to illustrate the theory for a GaAs/AlAs system. Electron states are considered to be confined within a QWW with finite and infinite potential barriers. We also assume single parabolic conduction and valence bands. The emission spectra are discussed for different scattering configurations and the selection rules for the processes are also studied. Singularities in the spectra are found and interpreted.

The differential cross-section for an electron Raman scattering process in a semiconductor quantum wire in the presence of an external magnetic field perpendicular to the plane of confinement is calculated. We assume a single parabolic conduction band. The emission spectra for different scattering configurations and the selection rules for the processes are studied. Singularities in the spectra are found and interpreted. The electron Raman scattering studied here can be used to provide direct information about the electron band and subband structure of these confinement systems. The magnetic field distribution is considered constant with value B 0 inside the wire and zero outside.

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In this work, the electron states corresponding to a semiconductor quantum well wire grown on a GaAs/AlGaAs matrix with a cylindrical symmetry, in the presence of an external electric field which is homogenous and perpendicular to the axis of the system, is obtained. This study takes into consideration the partial and total confinement of the charge carriers, and assumes T=0 K. The model on which this is based considers a system of parabolic bands, which unfolds in a system of sub-bands due to confinement. In addition, the selection rules for intraband and interband optic transitions are studied.