Zobrazeno 1 - 10
of 36
pro vyhledávání: '"A. S. Karakashian"'
Autor:
Joseph Shahbazian, A. S. Karakashian
Publikováno v:
International Journal of Modern Physics B. 23:3205-3211
In this letter, the influence of an applied electric field on a periodic structure composed of alternating layers of DPS (Double Positive index of refraction) and DNG (Double Negative index of refraction) has been studied. We present theoretical and
Autor:
L. R. Ram-Mohan, William D. Goodhue, A. S. Karakashian, Andrew J. Gatesman, Ahmer Naweed, Vinod M. Menon, Jerry Waldman
Publikováno v:
Physica E: Low-dimensional Systems and Nanostructures. 15:197-201
The observation of terahertz (THz) intersubband emission from GaAs/AlGaAs quantum cascade structures employing higher energy interface and barrier confined AlAs-like phonons for depopulation is reported. Emission is observed at 12.0 meV (2.9 THz ) an
Publikováno v:
Physica B: Condensed Matter. :212-215
We present evidence of terahertz emission from electrically injected GaAs/AlGaAs quantum cascade structures employing interface phonons for depopulation. Electroluminescence is observed at 17.5 meV (4.2 THz or 71 μm) with full-width at half-maximum
Publikováno v:
Journal of Applied Physics. 88:5262-5267
We present a detailed study of the electron-LO phonon interaction in a triple quantum well structure, which acts as the active region in an intersubband terahertz emitter. The phonon modes of the heterostructure were calculated using a transfer matri
Publikováno v:
Physica E: Low-dimensional Systems and Nanostructures. 7:52-57
The dependence of waveguide design parameters on the performance of a GaAs/AlGaAs quantum cascade laser emitting at 77 μm is theoretically evaluated. We propose a new waveguiding scheme for modal confinement at such long wavelengths. An artificially
Publikováno v:
Physica B: Condensed Matter. 228:239-244
The surface states in a finite superlattice in an electric field using the stair case approximation are studied. The eigenenergy equation is derived by the transfer matrix technique. The dependence of eigenenergy and probability profile on the electr
Publikováno v:
Journal of Applied Physics. 95:2930-2932
Observation of experimental negative differential resistance at room temperature due to electron tunneling in a multiple-step single-barrier GaAlAs heterostructure is reported. Theoretical investigations of a three-step single-barrier heterostructure
Autor:
A. S. Karakashian, A. R. Frederickson
Publikováno v:
Journal of Applied Physics. 77:1627-1634
We have found a capacitance‐voltage method to measure the spatial profile of majority carrier trap concentration in and near the depletion region of an abrupt p‐n semiconductor junction. The method is analogous to the standard capacitance‐volta
Autor:
Ahmer Naweed, V. Badami, Vinod M. Menon, Jerry Waldman, William D. Goodhue, L. R. Ram-Mohan, Andrew J. Gatesman, A. S. Karakashian, J. Plant
Publikováno v:
Applied Physics Letters. 80:2454-2456
We report the realization of a GaAs/AlGaAs quantum-cascade terahertz emitter capable of emitting at two entirely different frequencies from the same structure. This is realized through judicious wavefunction engineering of the relevant electronic sta
Publikováno v:
Applied optics. 30(21)
An array of Ag-Ti-n-GaAs grating photodiodes was designed and fabricated, with each diode having an active area with a diameter of 400 microm. Both electrical and optical characterizations were performed. We have made two experimental observations co