Open Access. Powered by Scholars. Published by Universities.®

Electrical and Computer Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

1993

Discipline
Institution
Keyword
Publication
Publication Type

Articles 241 - 246 of 246

Full-Text Articles in Electrical and Computer Engineering

Minority-Carrier Mobility Enhancement In P+ Ingaas Lattice Matched To Inp, E. S. Harmon, Michael L. Lovejoy, Michael R. Melloch, Mark S. Lundstrom, D. Ritter, R. A. Hamm Jan 1993

Minority-Carrier Mobility Enhancement In P+ Ingaas Lattice Matched To Inp, E. S. Harmon, Michael L. Lovejoy, Michael R. Melloch, Mark S. Lundstrom, D. Ritter, R. A. Hamm

Department of Electrical and Computer Engineering Faculty Publications

Minority electron mobilities in pf-In0.ssGac4, As have been measured with the zero field time-of-flight technique. The room-temperature (297 K) minority electron mobilities for p+-In,, 53Gac47A~ doped 0.9 and 3.1 x 10” cmm3 are found to be 2900 and 3300 cm* V-’ s-l, respectively. These are the first measurements to demonstrate enhancement in minority-carrier mobility as doping is increased for heavily doped Ines3Gae.4+s. This enhancement in mobility as doping is increased is similar to that observed in p+-GaAs, which has been attributed to reductions in plasmon and carrier-carrier scattering between minority electrons and majority holes.

Go to article

Concentration‐Dependent Optical‐Absorption Coefficient In N‐Type Gaas, Gregory Benedict Lush, H. F. Macmillan, S. Asher, Michael R. Melloch, Mark S. Lundstrom Jan 1993

Concentration‐Dependent Optical‐Absorption Coefficient In N‐Type Gaas, Gregory Benedict Lush, H. F. Macmillan, S. Asher, Michael R. Melloch, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

The doping-dependent, near-band-edge optical-absorption coefficient CY(h v) was deduced from optical transmission measurements in n-type GaAs thin films. The selenium-doped films were grown by metalorganic chemical-vapor deposition and do ed to produce room-temperature electron concentrations from 1.3 x 10” to 3.8X 1018 cm- P . The transmission measurements covered photon energies between 1.35 and 1.7 eV and were performed on double heterostructures with the substrate removed by selective etching. The results show good qualitative agreement with previous studies and good quantitative agreement, except for the heavily doped samples. For na=3.8 X 10” cme3, a( 1.42 eV> is approximately four times …

Go to article

Experimental Observation Of A Minority Electron Mobility Enhancement In Degenerately Doped P-Type Gaas, E. S. Harmon, Michael L. Lovejoy, Michael R. Melloch, Mark S. Lundstrom, T. J. De Lyon, J. M. Woodall Jan 1993

Experimental Observation Of A Minority Electron Mobility Enhancement In Degenerately Doped P-Type Gaas, E. S. Harmon, Michael L. Lovejoy, Michael R. Melloch, Mark S. Lundstrom, T. J. De Lyon, J. M. Woodall

Department of Electrical and Computer Engineering Faculty Publications

The variation of minority electron mobility with doping density in p+-GaAs has been measured with the zero-field time-of-flight technique. The results from a series of nine GaAs films doped between 1 X lOI and 8 X 10” cmm3 show the mobility decreasing from 1950 cm2 V-’ s-l at 1 X 10” cmm3 to 1370 cm2 V-l s-l at 9X 10” cmB3. For the doping range 9 x 1018-8x 1019 cme3, the decreasing trend in mobility is reversed. The measured mobility of 3710 cm2 V-’ s-l at 8 X 10” cmp3 is about three times higher than the measured value at …

Go to article

Feature Extraction And Classification Algorithms For High Dimensional Data, Chulhee Lee, David Landgrebe Jan 1993

Feature Extraction And Classification Algorithms For High Dimensional Data, Chulhee Lee, David Landgrebe

Department of Electrical and Computer Engineering Technical Reports

In this research, feature extraction and classification algorithms for high dimensional data are investigated. Developments with regard to sensors for Earth observation are moving in the direction of providing much higher dimensional multispectral imagery than is now possible. In analyzing such high dimensional data, processing time becomes an important factor. With large increases in dimensionality and the number of classes, processing time will increase significantly. To address this problem, a multistage classification scheme is proposed which reduces the processing time substantially by eliminating unlikely classes from further consideration at each stage. Several truncation criteria are developed and the relationship between …

Go to article

Pump And Signal Cross Saturation In Cw Dye Lasers, Lee W. Casperson, A. C. Wilson, W. J. Sandle Jan 1993

Pump And Signal Cross Saturation In Cw Dye Lasers, Lee W. Casperson, A. C. Wilson, W. J. Sandle

Electrical and Computer Engineering Faculty Publications and Presentations

It is well known that the signal output intensity from a dye laser oscillator depends directly on the pump intensity. The opposite effect, the dependence of the transmitted pump intensity on the signal intensity, is studied in detail. The theoretical results are compared with experimental data obtained using an argon‐laser‐pumped rhodamine 6G dye laser.

Go to article

Ultrashort‐Pulse Propagation In Dye Laser Amplifiers, Shuanghua Jiang, Lee W. Casperson Jan 1993

Ultrashort‐Pulse Propagation In Dye Laser Amplifiers, Shuanghua Jiang, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

A semiclassical model is presented for ultrashort‐pulse dye laser amplifiers. The model permits a discussion of important aspects of short‐pulse amplification such as pulse shape, pulse energy, and gain saturation. Coherence effects are found to be important in characterizing the evolution of amplified pulses in the subpicosecond and femtosecond regimes. The results are compared with those obtained using the corresponding rate equation model.

Go to article

First Prev