We theoretically study the absorption in grating coupled quantum wells in a cavity. We describe the coupling between the three oscillators present in the structure: the intersubband transition, the grating and cavity modes. We show that optical mode anticrossings should be observed. The splitting between the cavity mode and the intersubband transition is calculated but its experimental observat...

Improving the performance of the QCL through block diagram as well as mathematical models is the main scope of this paper. In order to enhance the performance of the underlined device, the mathematical model parameters are used in a reliable manner in such a way that the optimum behavior was achieved. These parameters play the central role in specifying the optical characteristics of the consid...

We demonstrate a quantum dash quantum cascade photodetector (QDash-QCD) by incorporating self-assembled InAs quantum dashes into the active region of a long wave infrared QCD. Sensitive photoresponse to normal incident light at 10 μm was observed, which is attributed to the intersubband (ISB) transitions in the quantum well/quantum dash (QW/QDash) hybrid absorption region and the following tran...

We propose a novel artificial medium, which locally provides both the optical nonlinearity and simultaneously the phasematching for the macroscopic build-up of the generated field. This is achieved by a special assembly of semiconductor quantum wells, which by careful design are both nonlinear and appropriately dispersive. A critical point for a practical realization of this meta-material is it...

A solid state broad band amplifier of terahertz radiation ~1.5–4 THz!, based on intersubband transitions of hot holes in p-Ge is demonstrated. The gain is investigated as a function of applied magnetic and electric fields by transmission measurements using a laser system with two p-Ge active crystals, when one operates as an oscillator and one as an amplifier. A peak gain higher than usually re...

Electronic and optoelectronic properties of SiGe/Si self-assembled quantum dots are calculated by the eight-band k"p method with a revised set of parameters. The model confirms that the Si12xGex transforms to a type-II structure when x is greater than 0.25 and given accurate effective masses for Si and Ge. The polarization dependent absorption spectra show a behavior quite different from what i...