static properties, relatively intensity noise and intensity modulation response in quantum cascade lasers (qcls) studied theoretically in this paper. the present rate equations model consists of three equations for the electrons density in the conduction band and one equation for photons density in cavity length. two equations were derived to calculate the noise and modulation response. calcula...

We present an optimized design for GaAs/AlGaAs quantum cascade lasers operating at ‎‎4.1THz. This was based on a three-well active module with diagonal radiative transition. This ‎was performed by modifying the existing model structure, to reduce the parasitic anticrossings ‎‎(leakage currents) as well as the optical gain linewidth. While the gain FWHM was reduced by ‎more than 50% the gain pea...

The amplitude-phase coupling factor a (linewidth enhancement factor) is compared in typical semiconductor quantum-well and bulk double heterostructure lasers. As a direct consequence of the reduction of the differential gain, there is no reduction of a in the single quantum-well lasers compared to the bulk lasers. The number of quantum wells strongly affects the amplitude-phase coupling in quan...