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|Title:||Wavelength Modified and Strained-Layer Quantum-Well Heterostructure and Superlattice Lasers (aluminum-Gallium - Arsenide)|
|Author(s):||Camras, Michael David|
|Department / Program:||Electrical Engineering|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Subject(s):||Engineering, Materials Science|
|Abstract:||The effects of wavelength modification and strained layers on quantum-well heterostructure (QWH) and superlattice (SL) lasers grown by metalorganic chemical vapor deposition (MOCVD) are investigated. Size quantization, high pressure, and thermal annealing are the methods used to alter the output energy of these lasers. Stimulated emission in strained-layer QWH's and SL's is demonstrated, and the form of their failure is examined.
Size quantization is used to increase the energy of the carriers in the (GAMMA), L, and X bands of a QWH. The Kronig-Penney model is used to predict the high energy limit of laser operation of QWH's in the AlGaAs system. High energy laser operation from various AlGaAs QWH's is demonstrated.
High pressure shifts the energy of the (GAMMA), L, and X bands. Photopumped laser operation of a QWH subjected to high pressure (0-11 kbar) is examined.
Thermal annealing at high temperatures (875-1000(DEGREES)C) has been used to change the band edge profile of QWH's and the energy of the laser output. The energy levels of the annealed quantum-well crystal are approximated by fitting a modified Poschl-Teller potential to the band-edge profile as modified by layer (Al-Ga) interdiffusion.
Stimulated emission data are also presented on a large variety of QWH's and SL's. These structures consist of barrier-well combinations of thickness <(, )150 (ANGSTROM) made of GaAs-InGaAs, GaAsP-GaAs, and GaAsP-InGaAs. All of these heterostructures are grown on a GaAs substrate with and, in some cases, without a graded layer. The strain range between 0.2 x 10('-3) and 12.5 x 10('-3) is examined.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1984.
|Date Available in IDEALS:||2014-12-15|
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Dissertations and Theses - Electrical and Computer Engineering
Dissertations and Theses in Electrical and Computer Engineering
Graduate Dissertations and Theses at Illinois
Graduate Theses and Dissertations at Illinois