Resonant second harmonic generation by a semiconductor quantum well in electric field

et al. 2004

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Article:Savic, I., Milanovic, V., Ikonic, Z. et Abstract-The design of ZnCdSe-ZnMnSe-based quantum wells is considered, in order to obtain a large shift of the peak absorption wavelength in the far infrared range, due to a giant Zeeman splitting with magnetic field, while maintaining a reasonably large value of peak absorption. A triple quantum-well structure with a suitable choice of parameters has been found to satisfy such requirements. A maximal tuning range between 14.6 and 34.7 meV is obtained, when the magnetic field varies from zero to 5 T, so the wavelength of the absorbed radiation decreases from 85.2 to 35.7 m with absorption up to 1.25% at low temperatures. These structures might form the basis for magnetic field tunable photodetectors and quantum cascade lasers in the terahertz range.Index Terms-Infrared detectors, manganese alloys, magnetic field effects, quantum wells, quantum theory, tunable circuits and devices.

Section: Numerical Results and Discussionmentioning

confidence: 99%

Dilute magnetic semiconductor quantum-well structures for magnetic field tunable far-infrared/terahertz absorption

Savić

et al. 2004

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“…Here, we have taken into account the position-dependent effective mass, and the self-consistent potential. The latter is calculated by iteratively solving the Schrödinger and Poisson equations [31]. Thus, we have designed a five-layer structure: Al Ga As (18 Å)-Al Ga As (45 Å)-Al Ga As (44 Å)-GaAs (51 Å)-Al Ga As (30 Å), embedded in Al Ga As outer barrier bulk, Fig.…”

Section: Numerical Results and Discussionmentioning

confidence: 99%

Gain optimization in optically pumped AlGaAs unipolar quantum-well lasers

Tomić

2001

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Abstract-A method is described for the optimized design of quantum-well (QW) structures, in respect to maximizing the stimulated gain in optically pumped intersubband lasers. It relies on applying supersymmetric quantum mechanics (SUSYQM) to an initial Hamiltonian, in order to both map one bound state below the spectral range of the initial Hamiltonian, and to generate a parameter-controlled family of isospectral Hamiltonians with the desired energy spectrum. By varying the control parameter, one changes the potential shape and, thus, the values of dipole matrix elements and electron-phonon scattering matrix elements. The use of this procedure is demonstrated by designing smoothly graded and stepwise-constant Al Ga 1 As ternary alloy QWs, with the self-consistent potential taken into account. Finally, the possibility of employing layer interdiffusion to get optimal smooth potentials is discussed.Index Terms-Layer interdiffusion, quantum-well lasers, supersymmetric quantum mechanics.

“…The central region of the shallow well was doped (sheet density cm ) and an external electric field (47 kV/cm) was applied across the structure to provide favorable alignment of levels, and enable strong coupling of levels 2 and 3 ( meV). The dipole moments were calculated using the self-consistent procedure [19], and amount to Å, , , , . An average electron concentration is taken to be cm .…”

Section: Numerical Results and Discussionmentioning

confidence: 99%

Second harmonic generation at the quantum-interference induced transparency in semiconductor quantum wells: the influence of permanent dipole moments

Kočinac

2001

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Abstract-The influence of permanent dipole moments of quantized states on intersubband second harmonic generation based on quantum-interference induced transparency in semiconductor quantum wells is explored using the harmonic balance method. The permanent moments are found to be quite important: they affect the transparency condition, especially at larger pump intensities. Hence, both the conversion efficiency and the optimal interaction path length change significantly when accounting for the permanent moments, and the conversion efficiency is reduced.Index Terms-Fano-interference, quantum interference, transparency.