Intersubband optical transitions at short wavelengths in strain-compensated In0.70Ga0.30As—AlAs double quantum wells are investigated by means of mid-infrared absorption. Trade-offs between achieving a high transition energy and a large oscillator strength of the two highest-energy intersubband transitions using our strain-compensation approach are analyzed as a function of the widths of the tw...

a simple semi-phenomenological model, which accurately predicts the dependence of thresholdcurrent for temperature of resonant-phonon three well quantum cascade laser based on verticaltransitions is offered. we found that, the longitude optical phonon scattering of thermally excitedelectrons is the most important limiting factor for thermal performance of high frequency thz qcls.in low frequenc...

Optical intersubband transitions (ISTs) for both in-plane polarization (TE) and normalto-plane polarization (TM) in p-type Si1-xGex/Si multiple quantum wells (MQWs) are investigated using 14-band k⋅p model combined with the envelope-function Fourier expansion method. The results show that the amplitudes of different intersubband transitions for TE and TM polarizations, and the overall absorptio...

We report the first demonstration of a solid state laser passively mode-locked through the saturable absorption of short-wavelength intersubband transitions in doped quantum wells: a continuous wave Ti:sapphire laser end-pumped Tm,Ho:YAG laser at the center wavelength of 2.091 mum utilizing intersubband transitions in narrow In(0.53)Ga(0.47)As/Al(0.53)As(0.47)Sb quantum wells. Stable passive mo...

We have investigated a solid–state design advanced (Soref et al. SPIE Proceedings, vol. 3795, 516 (1999)) to achieve Terahertz-Amplification-by-the-Stimulated-Emission-of-Radiation (TASER). The original design was based on lightto heavy-hole intersubband transitions in SiGe/Si heterostructures. This work adapts the design to electron intersubband transitions in the more readily available GaAs/G...

We study the low-intensity light pulse propagation through an asymmetric double quantum well via Fanotype interference based on intersubband transitions. The propagation of the pulse across the quantum well is studied analytically and numerically with the coupled Maxwell-Schrödinger equations. We show the generation of ultraslow bright and dark optical solitons in this system. Whether the solit...

We suggest the use of the refractive-index changes associated with the intersubband transitions in quantum wells for phase matching in nonlinear materials. An improvement in the conversion efficiency of mid-IR second-harmonic generation by almost 2 orders of magnitude over non-phase-matched bulk GaAs is predicted. We also show that the linear phase contributions of intersubband transitions used...

Strong electric-field transients resonant to intersubband transitions in n-type modulation-doped GaAs/AlGaAs quantum wells induce coherent Rabi oscillations, which are demonstrated by a phase-resolved measurement of the light emitted by the sample. The time evolution of the intersubband polarization is influenced by Coulomb-mediated many-body effects. The subpicosecond period and the phase of t...

We will present a detailed investigation of intersubband transitions process in core-multi shells quantum dots. The confined wave functions and eigenenergies of electrons in quantum dots have been calculated under the effective-mass approximation by solving a three-dimensional Schrodinger equation. Excellent dependence is found between size effects, time relaxation and degenerate four wave mixi...