Properties of Aluminium Gallium Arsenide
Properties of Aluminium Gallium Arsenide

Author: Sadao Adachi

Publisher: IET

Published: 1993

Total Pages: 354

ISBN-13: 9780852965580

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The alloy system A1GaAs/GaAs is potentially of great importance for many high-speed electronics and optoelectronic devices, because the lattice parameter difference GaAs and A1GaAs is very small, which promises an insignificant concentration of undesirable interface states. Thanks to this prominent feature, a number of interesting properties and phenomena, such as high-mobility low-dimensional carrier gases, resonant tunnelling and fractional quantum Hall effect, have been found in the A1GaAs/GaAs heterostructure system. New devices, such as modulation-doped FETs, heterojunction bipolar transistors, resonant tunnelling transistors, quantum-well lasers, and other photonic and quantum-effect devices, have also been developed recently using this material system. These areas are recognized as not being the most interesting and active fields in semiconductor physics and device engineering.

Design and Optical Characterization of Gallium Arsenide Aluminum Arsenide Material System Reflective Modulators for Mid-infrared Free Space Optical Applications Using Solid-source Molecular Beam Epitaxy
Design and Optical Characterization of Gallium Arsenide Aluminum Arsenide Material System Reflective Modulators for Mid-infrared Free Space Optical Applications Using Solid-source Molecular Beam Epitaxy

Author: Stanley Ikpe

Publisher:

Published: 2013

Total Pages: 160

ISBN-13:

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With the ever-growing usage of free space optical communication implementations, new innovations are currently being made to help improve the quality of transmission of these systems. One particular method employed to help improve transmission efficiency of optical links is shifting the transmission wavelength into the mid-infrared spectrum. Studies have shown sufficient increase in atmospheric transmission at and around mid-infrared wavelengths (near 3-5 mm). In order to successfully implement such systems at these wavelengths, devices must first be designed that are capable of optical communication operation at such wavelengths. One such device common in modern free space optical systems is the reflective modulator. This device minimizes the pointing and tracking associated with establishing free space optical connections. In this dissertation, a free space optical reflective modulator is designed using Gallium Arsenide and Aluminum Arsenide (GaAs/AlAs) to operate at midinfrared transmission wavelengths. The reflective modulator consists of multiple quantum well modulator (QWM) atop of a distributed Bragg reflector (DBR). The physical device characteristics are analyzed and the device functionality evaluated using optical characterization techniques.

Manufacturability of Gallium Arsenide/aluminum Gallium Arsenide Lasers Grown by Molecular Beam Epitaxy
Manufacturability of Gallium Arsenide/aluminum Gallium Arsenide Lasers Grown by Molecular Beam Epitaxy

Author: Sridhar V. Iyer

Publisher:

Published: 1994

Total Pages:

ISBN-13:

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The performance of high-power graded index separate confinement heterostructure single quantum well lasers grown by molecular beam epitaxy depends primarily on the quality of $Alsb{x}Gasb{1-x}As$ layers, the interface roughness, and the control of residual oxygen incorporation into the active region. Based on MBE growth experiments, a model for the incorporation, desorption and accumulation of oxygen during epitaxial growth of optical quality AlGaAs layers is proposed and validated. Based on this model, an optimal growth scheme for MBE grown GaAs/AlGaAs lasers is demonstrated. Over the growth of approximately one hundred and fifty lasers in a concurrent research, development, and manufacturing environment, the reduction of residual oxygen incorporation in GRINSCH-SQW lasers was found to be in excellent correlation with lower threshold density, higher quantum well photoluminesence intensity, and secondary ion mass spectroscopy data. The high growth temperatures required to prevent oxygen incorporation in the quantum well result in additional technical obstacles stymieing full exploitation of the growth technology for use in the manufacture of integrated opto-electronic circuits and systems. The inherent difficulties in accurately measuring growth temperature in MBE systems and the gallium desorption during high temperature growth can lead to nonuniformities in cladding material composition. These nonuniformities can lead to an asymmetrical waveguiding structure with distorted optical output characteristics. Distortions in the radiated optical pattern can greatly affect the alignment and coupling efficiency between laser diodes and optical fibers or other electro-optical systems in integrated opto-electronic applications. A two-dimensional dielectric waveguide simulator has been used to analyze the optical properties of GRINSCH GaAs/AlGaAs lasers with asymmetrical cladding structures induced by noise in growth temperature measurement. Through this analysis, an optimal device structure which has the desired optical characteristics and is less sensitive to cladding composition asymmetries is demonstrated.

Properties of Gallium Arsenide
Properties of Gallium Arsenide

Author: M. R. Brozel

Publisher: Inst of Engineering & Technology

Published: 1996

Total Pages: 981

ISBN-13: 9780852968857

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It was in 1986 that INSPEC (The Information Division of the Institution of Electrical Engineers) published the book Properties of Gallium Arsenide. Since then, major developments have taken place. This third edition is comprised of 150 specially commissioned articles contributed by experts from the USA, Europe and Japan.

Characterization and Simulations of Long Wavelength Indium Aluminum Gallium Arsenideindium Phosphide Lasers
Characterization and Simulations of Long Wavelength Indium Aluminum Gallium Arsenideindium Phosphide Lasers

Author: Julie Nkanta

Publisher:

Published: 2008

Total Pages: 0

ISBN-13:

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This thesis studies the characterization and simulation of long wavelength indium aluminium gallium arsenide (InAlGaAs) lattice-matched to indium phosphide (InP) diode laser, emitting between 1.648 to 1.7 mum in wavelength. The active region of one laser diode sample consists of six In0.69Ga 0.31As quantum wells (1.0% compressive strain) and seven In0.52 Al0.36Ga0.12As unstrained barriers. The lasers are grown using digital alloy molecular beam epitaxy (MBE). The band diagram analysis shows a large conduction band offset which is typical of InAlGaAs lasers. The geometry-dependent and temperature-dependent measurement as well as the laser optical gain, loss and spectral properties were carried out and comparison done for different ridge widths (1.2 to 2.8mum), cavity lengths (555 to 2200mum) and temperature range between 25 and 70°C. The output power as a function of current characteristics reveals threshold current increase with cavity lengths and ridge widths with thermal roll-off occurring at higher injection currents. The slope efficiency and external differential quantum efficiency increases for the narrowest and widest ridge widths within the same cavity length laser device but decreases with increase in cavity length. The temperature analysis shows longer cavity length lasers exhibit better temperature characteristic than the shorter cavity length laser devices indicating the better thermal stability of the longer cavity lasers. Temperature elevations also caused increase in threshold current and decrease in efficiencies. The temperature distribution shows a higher temperature in the active region than the operating temperature due to self heating of the laser devices in continuous wave operation. The optical spectrum exhibits red-shifting of the emission wavelength with increasing bias current and temperature.