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Title: Theoretical analysis of multiple quantum-well, slow-light devices under applied external fields using a fully analytical model in fractional dimension

Abstract

We report a theoretical study of optical properties of AlGaAs/GaAs multiple quantum-well (MQW), slow-light devices based on excitonic population oscillations under applied external magnetic and electric fields using an analytical model for complex dielectric constant of Wannier excitons in fractional dimension. The results are shown for quantum wells (QWs) of different width. The significant characteristics of the exciton in QWs such as exciton energy and exciton oscillator strength (EOS) can be varied by application of external magnetic and electric fields. It is found that a higher bandwidth and an appropriate slow-down factor (SDF) can be achieved by changing the QW width during the fabrication process and by applying magnetic and electric fields during device functioning, respectively. It is shown that a SDF of 10{sup 5} is obtained at best. (slowing of light)

Authors:
;  [1]
  1. Photonics Research Laboratory, Electrical Engineering Department, AmirKabir University of Technology, Hafez Ave., Tehran (Iran, Islamic Republic of)
Publication Date:
OSTI Identifier:
22395801
Resource Type:
Journal Article
Resource Relation:
Journal Name: Quantum Electronics (Woodbury, N.Y.); Journal Volume: 45; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM ARSENIDES; ELECTRIC FIELDS; EXCITONS; GALLIUM ARSENIDES; OPTICAL PROPERTIES; OSCILLATIONS; OSCILLATOR STRENGTHS; PERMITTIVITY; QUANTUM WELLS

Citation Formats

Kohandani, R, and Kaatuzian, H. Theoretical analysis of multiple quantum-well, slow-light devices under applied external fields using a fully analytical model in fractional dimension. United States: N. p., 2015. Web. doi:10.1070/QE2015V045N01ABEH015596.
Kohandani, R, & Kaatuzian, H. Theoretical analysis of multiple quantum-well, slow-light devices under applied external fields using a fully analytical model in fractional dimension. United States. doi:10.1070/QE2015V045N01ABEH015596.
Kohandani, R, and Kaatuzian, H. Sat . "Theoretical analysis of multiple quantum-well, slow-light devices under applied external fields using a fully analytical model in fractional dimension". United States. doi:10.1070/QE2015V045N01ABEH015596.
@article{osti_22395801,
title = {Theoretical analysis of multiple quantum-well, slow-light devices under applied external fields using a fully analytical model in fractional dimension},
author = {Kohandani, R and Kaatuzian, H},
abstractNote = {We report a theoretical study of optical properties of AlGaAs/GaAs multiple quantum-well (MQW), slow-light devices based on excitonic population oscillations under applied external magnetic and electric fields using an analytical model for complex dielectric constant of Wannier excitons in fractional dimension. The results are shown for quantum wells (QWs) of different width. The significant characteristics of the exciton in QWs such as exciton energy and exciton oscillator strength (EOS) can be varied by application of external magnetic and electric fields. It is found that a higher bandwidth and an appropriate slow-down factor (SDF) can be achieved by changing the QW width during the fabrication process and by applying magnetic and electric fields during device functioning, respectively. It is shown that a SDF of 10{sup 5} is obtained at best. (slowing of light)},
doi = {10.1070/QE2015V045N01ABEH015596},
journal = {Quantum Electronics (Woodbury, N.Y.)},
number = 1,
volume = 45,
place = {United States},
year = {Sat Jan 31 00:00:00 EST 2015},
month = {Sat Jan 31 00:00:00 EST 2015}
}
  • The spin polarization under low electric fields (≤300 V/cm) at low temperatures has been studied in undoped InGaAs/AlGaAs multiple quantum well. The spin polarization was created by optical spin orientation using circularly polarized light and the inverse spin-Hall effect was employed to measure the spin polarization current. We observed an obvious spin depolarization especially at lower temperatures (80–120 K). We ascribed the spin depolarization of the photoinduced electrons to the heating effect from the low electric fields (the low field regime 50–300 V/cm). This spin depolarization due to the heating effect is sensitive to temperature and electric field, suggesting a wide range ofmore » potential applications and devices.« less
  • The external efficiency {eta}{sub {ital d}} of quantum well (QW) lasers is maximum at some characteristic laser length, which is dependent upon mirror reflectivities and the number of QWs in the active layer. The observed decrease in {eta}{sub {ital d}} in short lasers is caused by increased optical absorption associated with a high concentration of free carriers in the QW and the surrounding waveguide layer. The carriers spill into the waveguide because of QW subband filling in short cavity lasers with high threshold gains.
  • A multiple-stripe quantum well heterostructure laser diode operated in an external grating cavity is shown to exhibit the far-field radiation patterns of the ''supermode'' eigenstates predicted by coupled mode analysis. Data (approx.7330 A) are presented on a gain-guided laser array at various continuous (cw, 300 K) operating currents to illustrate the progression of the supermodes from double-lobed patterns (phase shift between emitters) to a single-lobed pattern (no phase shift between emitters). As the cavity wavelength is scanned a cyclical progression (2.8-A period) of far-field patterns (supermodes) is observed.
  • Sequential resonant tunneling is proposed to enhance the photocurrent and reduce recombination losses in photovoltaic devices based on multiple-quantum-well (MQW) heterostructures. An InGaAsP/InP MQW {ital p{endash}i{endash}n} diode with built-in sequential resonant tunneling has been fabricated, and demonstrates an increase in the photocurrent and reduction in photoluminescence intensity. These effects are attributed to the resonance tunneling effect. {copyright} {ital 1999 American Institute of Physics.}
  • We report on the band-edge stimulated emission in InGaN{endash}GaN multiple quantum well light-emitting diodes with varying widths and barrier thicknesses of the quantum wells. In these devices, we observe that the stimulated emission peak wavelength shifts to shorter values with decreasing well thickness. From the comparison of the results of the quantum mechanical calculations of the subbands energies with the measured data, we estimate the effective conduction- and valence-band discontinuities at the GaN{endash}In{sub 0.13}Ga{sub 0.87}N heterointerface to be approximately 130{endash}155 and 245{endash}220 meV, respectively. We also discuss the effect of stress on the estimated values of band discontinuities. {copyright} {italmore » 1997 American Institute of Physics.}« less