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Articles 331 - 360 of 427

Full-Text Articles in Materials Science and Engineering

Detection Of Residual Stress In Sic Mems Using Μ-Raman Spectroscopy, John C. Zingarelli Mar 2005

Detection Of Residual Stress In Sic Mems Using Μ-Raman Spectroscopy, John C. Zingarelli

Theses and Dissertations

Micro-Raman (µ-Raman) spectroscopy is used to measure residual stress in two silicon carbide (SiC) poly-types: single-crystal, hexagonally symmetric 6H-SiC, and polycrystalline, cubic 3C-SiC thin films deposited on Si substrates. Both are used in micro-electrical-mechanical systems (MEMS) devices. By employing an incorporated piezoelectric stage with submicron positioning capabilities along with the Raman spectral acquisition, spatial scans are performed to reveal areas in the 6H-SiC MEMS structures that contain residual stress. Shifts in the transverse optical (TO) Stokes peaks of up to 2 cm-1 are correlated to the material strain induced by the MEMS fabrication process through the development of phonon …

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Dynamic Characterization Of Thin Deformable Pvdf Mirror, Eric M. Trad Mar 2005

Dynamic Characterization Of Thin Deformable Pvdf Mirror, Eric M. Trad

Theses and Dissertations

Methodology for the design and fabrication of 5 inch diameter membrane-like mirror structures is explored, resulting in test articles with areal densities as low as 1.57 kg/m2 and a thickness of 1.5 mm. Each optical structure has 7 control patches etched into the PVDF layer, which can be used as actuators. These test articles are utilized to demonstrate the capabilities of an acquisition system to make measurements of static and dynamic actuation of the mirror surface. Static deformations are analyzed statistically and determined to yield maximum deformations in the actuated regions of -2.1 micro with a standard deviation of 0.33 …

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Tensile Stress Rupture Behavior Of A Woven Ceramic Matrix Composite In Humid Environments At Intermediate Temperature, Kevin J. Larochelle Mar 2005

Tensile Stress Rupture Behavior Of A Woven Ceramic Matrix Composite In Humid Environments At Intermediate Temperature, Kevin J. Larochelle

Theses and Dissertations

Stress rupture tests on the SylramicTM fiber with an in-situ layer of boron nitride, boron nitride interphase, and SiC matrix ceramic matrix composite were performed at 550°C and 750°C with 0.0, 0.2, or 0.6 atm partial pressure of water vapor, pH2O. The 550°C, 100-hr strengths were 75%, 65% and 51% of the monotonic room temperature tensile strength, respectively. At 750°C, the strengths were 67%, 51%, and 49%, respectively. Field Emission Scanning Electron Microscopy analysis estimated the total embrittlement times for 550°C with 0.0, 0.2, and 0.6 atm pH2O were >63 hrs, >38 hrs, and between …

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Effects Of Variable Contact Load On Fretting Fatigue Behavior Of Shot-Peened And Un-Peened Titanium Alloy, Chia-Hawa Lee Dec 2004

Effects Of Variable Contact Load On Fretting Fatigue Behavior Of Shot-Peened And Un-Peened Titanium Alloy, Chia-Hawa Lee

Theses and Dissertations

Fretting fatigue occurs between two components in contact under relative motion and reduces fatigue life when compared with plain fatigue. Shot-peening, on the other hand, is the most commonly used cold working process to improve material fatigue resistance in aeronautical industries. Nearly all work accomplished to date has assumed a constant contact load while investigating fretting fatigue. The primary goal of this study was to explore fretting fatigue behavior under constant and variable contact load configurations using both shot-peened and un-peened specimens made up of Ti-6Al-4V alloy. Contact loads were applied with four different frequencies. Applied axial loads were also …

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Monotonic, Creep-Rupture, And Fatigue Behavior Of Carbon Fiber Reinforced Silicon Carbide (C/Sic) At An Elevated Temperature, John M. Engesser Mar 2004

Monotonic, Creep-Rupture, And Fatigue Behavior Of Carbon Fiber Reinforced Silicon Carbide (C/Sic) At An Elevated Temperature, John M. Engesser

Theses and Dissertations

The main objective of this research effort was to examine the impact that cyclic loading frequency has on the life of a C/SiC composite at an elevated temperature of 550°C. Cyclic loading of C/SiC was investigated at frequencies of 375 Hz, 10 Hz, 1 Hz, and 0.1 Hz. Creep-Rupture tests and tests that were combinations of creep-rupture and fatigue were also accomplished. A monotonic tensile test was performed at 550°C and compared to a room temperature monotonic test. This study showed that an elevated temperature of 550°C has very little effect on the Ultimate Tensile Strength (UTS) of C/SiC. The …

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Optical Characterization And Modeling Of Compositionally Matched Indium Arsenide-Antimonide Bulk And Multiple Quantum Well Semiconductors, Scott C. Phillips Mar 2004

Optical Characterization And Modeling Of Compositionally Matched Indium Arsenide-Antimonide Bulk And Multiple Quantum Well Semiconductors, Scott C. Phillips

Theses and Dissertations

Indium arsenide-antimonide (InAsSb) semiconductors have been determined to emit in the 3-5 micrometer range, the window of interest for countermeasures against infrared electro-optical threats. This experiment set out to cross the bulk to quantum well characterization barrier by optically characterizing two sets of compositionally matched type I quantum well and bulk well material samples. Absorption measurements determined the band gap energy of the bulk samples and the first allowed subband transition for the quantum wells. By collecting absorption spectra at different temperatures, the trend of the energy transitions was described by fitting a Varshni equation to them. The expected result …

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Experimental And Computational Analysis Of Modes In A Partially Constrained Plate, Robert M. Vandawaker Mar 2004

Experimental And Computational Analysis Of Modes In A Partially Constrained Plate, Robert M. Vandawaker

Theses and Dissertations

The field of structural health monitoring (SHM) attempts to reduce labor and cost by allowing technicians to monitor selected properties of an aircraft's structure to detect impending failure. This research examines methods to detect damage to a thermal protection system (TPS) tile using representative 2024-T3 aluminum plates. Plates are subjected to modal analysis in single and joined conditions in an attempt to provide the capability of sensing damage to a tile on the surface of a vehicle while the sensors remain on the superstructure of the airframe. Jointly, the development of a means to model the system using finite element …

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The Evaluation Of The Damping Characteristics Of A Hard Coating On Titanium, Christopher M. Blackwell Mar 2004

The Evaluation Of The Damping Characteristics Of A Hard Coating On Titanium, Christopher M. Blackwell

Theses and Dissertations

Engine failures due to fatigue have cost the Air Force an estimated $400 million dollars per year over the past two decades (Garrison, 2001). Damping treatments capable of reducing the internal stresses of fan and turbine blades to levels where fatigue is less likely to occur have the potential for reducing cost while enhancing reliability. This research evaluates the damping characteristics of magnesium aluminate spinel, MgO+Al2O3, (mag spinel) on titanium plates. The material and aspect ratio were chosen to approximate the low aspect ratio blades found in military gas turbine fans. The plates were tested with …

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Controlled-Stress Large-Area Pulsed Laser Deposition Of Yttria Stabilized Zirconia, Paul C. Rounsavall Sep 2003

Controlled-Stress Large-Area Pulsed Laser Deposition Of Yttria Stabilized Zirconia, Paul C. Rounsavall

Theses and Dissertations

The US Air Force has need of parabolic-shaped membrane mirrors for surveillance satellites. The current polymer membrane technology has been unable to overcome shape deformation problems caused by intrinsic stresses from the membrane casting and mounting processes. One proposed solution was to coat the membrane mirrors with a stressed coating to compensate for shape deformations. Thus, the research presented in this dissertation produced controlled-stress large-area pulsed laser deposition (PLD) grown thin films on polymer substrates and investigated optical time-of-flight (TOF) sensor systems and Raman spectroscopy for control for the PLD process with respect to thin film stress. Initially, the PLD-grown …

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Electrical Activation Studies Of Silicon Implanted Alx Gal-X N And Coimplanted Gan, Elizabeth A. Chitwood Mar 2003

Electrical Activation Studies Of Silicon Implanted Alx Gal-X N And Coimplanted Gan, Elizabeth A. Chitwood

Theses and Dissertations

A comprehensive study of the electrical activation of silicon implanted AlxGa1-xN was performed as a function ion dose, anneal temperature, and aluminum mole fraction, Also, GaN coimplanted with silicon and nitrogen was investigated. Room temperature Hall effect measurements were used to determine carrier concentration and mobility. All the samples had a 500 Å encapsulant of AlN, and were implanted at room temperature with 200 keV silicon ions at doses ranging from 1x1013 to 1x1015 /sq cm. The GaN was also implanted with nitrogen under the same conditions in doses of 9x1012 to 9x10 …

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Luminescence Studies Of Ion-Implanted Gallium Nitride And Aluminum Gallium Nitride, Erin N. Claunch Mar 2003

Luminescence Studies Of Ion-Implanted Gallium Nitride And Aluminum Gallium Nitride, Erin N. Claunch

Theses and Dissertations

Recently, research on the wide bandgap semiconductors such as GaN and Al(x)Ga(1-x)N became very popular for their applications on various devices. Therefore comprehensive and systematic luminescence studies of Si implanted AlxGa1-xN, Mg doped GaN, and Si+N implanted GaN grown on sapphire substrates by molecular beam epitaxial method have been made as a function of ion dose and anneal temperature.

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Characterization Of The Optical And Electrical Properties Of Proton-Irradiated 4h-Silicon Carbide, Heather C. Crockett Mar 2002

Characterization Of The Optical And Electrical Properties Of Proton-Irradiated 4h-Silicon Carbide, Heather C. Crockett

Theses and Dissertations

Epitaxial n-type 4H-silicon carbide (SiC) is irradiated with 2 MeV protons to evaluate the dislocation damage effects on the optical and electrical characteristics of the material. Semiconductor materials with a high tolerance to radiation fields have applications in several aerospace power and satellite systems. SiC is under investigation due to its potential for such space material applications. The optical properties of the material are investigated using temperature-dependent photoluminescence (PL) and the effects of proton irradiation on the electrical properties are evaluated using current-voltage measurements and constant-voltage deep level transient spectroscopy (CV-DLTS). Subsequent high-temperature thermal annealing and recovery of the irradiated …

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Fretting Fatigue Behavior Of A Titanium Alloy Ti-6al-4v At Elevated Temperature, Onder Sahan Mar 2002

Fretting Fatigue Behavior Of A Titanium Alloy Ti-6al-4v At Elevated Temperature, Onder Sahan

Theses and Dissertations

The purpose of this research is to investigate the fretting fatigue behavior of the titanium alloy Ti-6Al-4V at elevated temperature is investigated. Fretting and plain fatigue experiments are conducted at 260 °C. Crack initiation location and crack initiation orientation is measured and fretting and plain fatigue life data of the specimens from these tests are obtained. Fatigue parameters capable of predicting the number of cycles to specimen failure, the crack location and the crack orientation along the contact surface are analyzed. The parameters are calculated by using the computed stresses and strains obtained from the finite element analysis. The mechanisms …

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Smart Structures For Control Of Optical Surfaces, D. Michael Sobers Jr. Mar 2002

Smart Structures For Control Of Optical Surfaces, D. Michael Sobers Jr.

Theses and Dissertations

The development of lightweight, large-aperture optics is of vital importance to the Department of Defense and the US Air Force for advancing remote sensing applications and improving current capabilities. Synthetic polymer optics offer weight and flexibility advantages over current generation glass mirrors, but require active control to maintain tight surface figure tolerances. This research explores the feasibility of using imbedded piezoelectric materials to control optical surfaces. Membrane-based and stiff piezo-controlled mirrors were constructed to develop and validate control techniques. Test results verified that surface control on the order of tens of wavelengths is possible using these systems.

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Measurements Of Neutron Induced Surface And Bulk Defects In 4h Silicon Carbide, Kent T. Jones Mar 2002

Measurements Of Neutron Induced Surface And Bulk Defects In 4h Silicon Carbide, Kent T. Jones

Theses and Dissertations

Epitaxial n-type 4H-silicon carbide (SiC) is irradiated with 2 MeV protons to evaluate the dislocation damage effects on the optical and electrical characteristics of the material. The optical properties of the material are investigated using temperature-dependant photoluminescence (PL) and the effects of proton irradiation on the electrical properties are evaluated using current-voltage measurements and constant-voltage deep level transient spectroscopy (CV-DLTS). Subsequent high-temperature thermal annealing and recovery of the irradiated material is investigated over the temperature range of 900-1500°C. Proton-induced irradiation damage is apparent in the 4H-SiC material, affecting both the optical and electrical characteristics of the devices. The radiative behavior …

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Electrical Activation Studies Of Ion Implanted Gallium Nitride, James A. Fellows Nov 2001

Electrical Activation Studies Of Ion Implanted Gallium Nitride, James A. Fellows

Theses and Dissertations

A comprehensive and systematic electrical activation study of Si-implanted GaN was performed as a function of ion implantation dose, anneal temperature, and implantation temperature. Additionally, Mg-implanted GaN was also investigated. Temperature-dependent Hall effect measurements and photoluminescence (PL) spectra were used to characterize the samples. GaN wafers capped with AlN were implanted with Si ions at doses ranging from 1x1013 to 5x1015 cm-2 and annealed from 1050 to 1350 °C. The optimum anneal temperature for samples implanted with the higher Si doses is around 1350 °C, exhibiting nearly 100% electrical activation efficiency. Exceptional mobilities and carrier concentrations were …

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Time-Resolved Photoluminescence Of Inas/Gainsb Quantum Well Lasers, Michael R. Mckay Jun 2001

Time-Resolved Photoluminescence Of Inas/Gainsb Quantum Well Lasers, Michael R. Mckay

Theses and Dissertations

In the world of semiconductor photonic device fabrication, one important objective may be to extract as much light as possible from the device. In these devices, photons are created when electrons recombine with holes by transitioning from a high-energy state to a lower one. Unfortunately, electron-hole recombination does not always result in the formation of a photon. There are three basic types of recombination: the first results in the formation of a photon and is called radiative recombination; and the second and third, known as Shockley-Read-Hall and Auger recombination, result in the heating of the device and do not produce …

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Single-Sided Noninvasive Inspection Of Multielement Sample Using Fan-Beam Multiplexed Compton Scatter Tomography, Matthew A. Lange Jun 2001

Single-Sided Noninvasive Inspection Of Multielement Sample Using Fan-Beam Multiplexed Compton Scatter Tomography, Matthew A. Lange

Theses and Dissertations

As aircraft age, corrosion forms upon unobservable surfaces, particularly at the junction of the sheet aluminum and the steel rivets used to attach the sheets to the airframe, degrading the aircraft s airworthiness. Previous research developed a noninvasive technique for the evaluation of the material composition of aluminum surfaces, utilizing the information encoded in the energy spectra of Compton-scattered gamma emissions. The spectra are gathered by a six-element, high purity germanium detector array. A, first principles, deterministic computer code is used to reconstruct a two-dimensional map of the electron density of aluminum samples. Previous efforts, to image pure aluminum samples, …

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Photoluminescence Of Single Quantum Well Structures In Gallium Arsenide, Christian A. Bartholomew Mar 2001

Photoluminescence Of Single Quantum Well Structures In Gallium Arsenide, Christian A. Bartholomew

Theses and Dissertations

The continued development of state-of the-art semiconductor technologies and devices by the United States Air Force and the Department of Defense requires accurate and efficient techniques to evaluate and model these new materials. Of particular interest to the Air Force are quantum well structures which can be used for small-scale laser sources in fly-by-light applications, as efficient infrared countermeasures to heat-seeking missiles, or as advanced seekers in optically guided missiles. This thesis provides the initial experimental procedures and data necessary to begin producing accurate yet robust models. Although carrier effective masses could not be evaluated using hot-electron photoluminescence, photoluminescence excitation …

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Numerical Study Of Optical Delay In Semiconductor Multilayer Distributed Bragg Reflector And Tunable Microcavity Structures, Michael I. K. Etan Mar 2001

Numerical Study Of Optical Delay In Semiconductor Multilayer Distributed Bragg Reflector And Tunable Microcavity Structures, Michael I. K. Etan

Theses and Dissertations

The Air Force has a growing need for the greater bandwidth, speed, and flexibility offered by optical communication links. Future space systems and airborne platforms will most likely use optical signals for efficient power transmission and to minimize the possibility of spoofing and eavesdropping. Tunable optical delays play an important role in the implementation of free space optical communication links. The primary challenge in implementing these systems is the active maintenance of coherent wave fronts across the system's optical aperture. For space applications, this aperture may he hundreds of meters in diameter. Spatial segmentation of a large aperture into smaller …

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Optical And Etching Studies Of Native Aluminum Oxide Layers For Use In Microcavity Photonic Devices, William L. Bernhard Mar 2001

Optical And Etching Studies Of Native Aluminum Oxide Layers For Use In Microcavity Photonic Devices, William L. Bernhard

Theses and Dissertations

Optical communication and computing systems are required to meet future information transfer and processing needs. Microcavity devices serve as an enabling technology to implement and integrate optoelectronic systems. It is important to understand the optical and mechanical properties of materials utilize within microcavity devices. Only then is it possible to accurately model and analyze structures. Microcavity structures incorporating a high aluminum content AlGaAs layers are designed, grown, processed, and measured. The processing of these devices includes the conversion of high aluminum-content AlGaAs layers to native aluminum oxide (AlO) layers through the process of thermal oxidation. This selective conversion of microcavity …

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Fatigue Response Of Thin Stiffened Aluminum Cracked Panels Repaired With Bonded Composite Patches, Jason B. Avram Mar 2001

Fatigue Response Of Thin Stiffened Aluminum Cracked Panels Repaired With Bonded Composite Patches, Jason B. Avram

Theses and Dissertations

This research investigated the fatigue response of precracked and patched 2024-T3 Aluminum panels with stiffeners. Patches were single-sided, unidirectional three ply boron/epoxy. Stiffeners were 2024-T3 aluminum and were riveted and bonded on. Disbonds were introduced into the repair bondline by inserting teflon strips. Three disbond configurations were investigated rack tip disbond (CTD) located at the edge of the patch in the path of crack propagation, full-width disbond (FWD) covering the entire crack, and end disbond (ED) located at each end of the patch and covering the full width. Each repaired panel was subjected to tension/tension cyclic fatigue with a maximum …

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Mechanics Of A Functionally-Graded Titanium Matrix Composite, G. Brandt Miller Mar 2000

Mechanics Of A Functionally-Graded Titanium Matrix Composite, G. Brandt Miller

Theses and Dissertations

Functionally-graded Titanium Matrix Composites, (F/G TMCs) combine the ideal properties of titanium matrix composites with the more practical machining qualities of monolithic (unreinforced) alloy. This material shows great promise in application to aerospace structural components - even in parts whose design requirements have defied the use of composite materials in the past. Successful implementation of such a material would lead to enhanced aircraft performance. However, the basic properties of a functionally-graded titanium matrix composite need to be investigated. The composite/alloy transition region, or joint area, may be less strong than its constituents and therefore determine the overall performance of the …

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Optical Investigation Of Molecular Beam Epitaxy AlXGa1-XN To Determine Material Quality, Judith L. Mcfall Mar 2000

Optical Investigation Of Molecular Beam Epitaxy AlXGa1-XN To Determine Material Quality, Judith L. Mcfall

Theses and Dissertations

The purpose of this research was to determine the quality of AIGaN samples with various mole fractions of aluminum doped with silicon. The samples utilized for this study were composed of an AIN buffer layer sandwiched between the sapphire substrate and AIGaN epilayer grown by molecular beam epitaxy (MBE). Cathodoluminescence (CL) and photoluminescence (PL) were employed to determine the mole fraction of aluminum in each sample. These techniques also gave insight into the material's nonuniformity, defects, and impurities. CL was run at 4 different beam energies (2,5,10, & 15 keV) with four different currents (1,10,50, & 90 µA) for the …

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Chemical Mechanical Polishing Optimization For 4h-Sic, Craig L. Neslen Mar 2000

Chemical Mechanical Polishing Optimization For 4h-Sic, Craig L. Neslen

Theses and Dissertations

Scratch free surfaces are required for substrates used in epitaxial growth. Silicon carbide (SiC) is a substrate material that is used in the epitaxial growth of SiC, GaN, and InGaN electronic devices. Preliminary chemical mechanical polishing (CMP) studies of 1 3/8" 4H-SiC wafers were performed in an attempt to identify the polishing parameter values that result in a maximum material removal rate and thus reduce substrate polishing time. Previous studies reported increased material removal rates associated with increasing polishing temperature, slurry pH, pressure, and polishing pad speed. In the current study, the effects of temperature, slurry pH, polishing pressure, and …

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Effects Of Foreign Object Damage From Small Hard Particles On The High-Cycle Fatigue Life Of Ti-6a1-4v, Joseph L. Hamrick Ii Dec 1999

Effects Of Foreign Object Damage From Small Hard Particles On The High-Cycle Fatigue Life Of Ti-6a1-4v, Joseph L. Hamrick Ii

Theses and Dissertations

Thin rectangular samples of Ti-6Al-4V were damaged by four methods to represent foreign object damage found in turbine engine blades: 1) impact with 2 mm and 5 mm diameter glass spheres at 305 m/s, 2) impact with 2 mm and 4 mm diameter steel spheres at 305 m/s, 3) quasi-static displacement controlled indentation using steel chisels with 1 mm, 2 mm and 5 mm diameter tips and 4) shearing notches with a 2 mm diameter chisel point under a quasi-static loading condition. Finite element analysis was used to study the relationship between the stress state created by the plastic damage …

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Electrical And Optical Characterization Of Intrinsic And Ion-Implantation Induced Defects In 6h- And 4h-Sic, Michael B. Scott Dec 1999

Electrical And Optical Characterization Of Intrinsic And Ion-Implantation Induced Defects In 6h- And 4h-Sic, Michael B. Scott

Theses and Dissertations

Deep level transient spectroscopy (DLTS), Hall effect, and cathodolummescence (CL) measurements are used to characterize the intrinsic and ion-implantation induced defects in high-temperature (475 and 500 °C) ion-implanted epitaxial n-type 6H- and 4H-SiC, ion-implanted with Cr, Mg, Ar, N, and P atoms. Comparison of room-temperature and high-temperature ion-implanted 6H-SiC:Mg and :Cr indicate the significance of high-temperature ion implantation on the activation of the ion-implanted atoms and damage-recovery of the crystalline lattice. The effects of high-temperature annealing on both damage-recovery and implanted ion activation are detected and analyzed, from 1200 to 1800 °C. Trap parameters of both damage-related and species-related defects …

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Electrical Characterization Of Ion-Implanted 4h-Silicon Carbide, Christian P. Morath Mar 1999

Electrical Characterization Of Ion-Implanted 4h-Silicon Carbide, Christian P. Morath

Theses and Dissertations

Electrical characterization has been performed on ion-implanted p-type 4H-SiC to assess the activation efficiency and implantation-related damage recrystallization with the intention of developing an implantation/annealing scheme. Low doped (Na - Nd = 5x10(exp 15)/cu cm) epitaxial p-type layers grown by MOCVD were implanted with Al or B at doses ranging from 1x10(exp 13) to 1x10(exp 14)/sq cm at room temperature or 500 deg. C. The electrical technique of Temperature Dependent Hall Effect (TDHE) indicated that Al and B act as shallow acceptors 4H-SiC with ionization energies of ^252 and ^285 meV, respectively. The highest activation efficiency for Al and B …

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Measurement Of Ultrafast Carrier Recombination Dynamics In Mid-Infrared Semiconductor Laser Material, William T. Cooley Dec 1997

Measurement Of Ultrafast Carrier Recombination Dynamics In Mid-Infrared Semiconductor Laser Material, William T. Cooley

Theses and Dissertations

Shockley-Read-Hall, radiative, and Auger recombination rates in mid-infrared laser structures are measured and reported using time resolved photoluminescence (TRPL) frequency upconversion. The mid-IR lasers studied were actual InAsSb/InAlAsSb multiple-quantum-well (MQW) diode lasers emitting near 3.3 micrometers which were previously characterized for laser performance. This effort extends the initial studies and reports on the carrier recombination dynamics. Shockley-Read-Hall, radiative and Auger recombination rates at low temperature (77 K) were measured and found to be ASRH ≈ 10 x 107sec-1, Brad ≈ 2 x 10-10 cm3sec-1 and CAuger < 10-29 cm6 …

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Experimental Investigation Of Nonlinear Dynamics In Single Mode Semiconductor Laser Diodes With Phase Conjugate Feedback, Gordon T. Hengst Aug 1997

Experimental Investigation Of Nonlinear Dynamics In Single Mode Semiconductor Laser Diodes With Phase Conjugate Feedback, Gordon T. Hengst

Theses and Dissertations

The semiconductor laser diode offers a unique system to investigate nonlinear dynamics when optical feedback is applied. Although there is extensive research of laser diodes with optical feedback from normal dielectric mirrors, very little has been done experimentally to analyze the effects of degenerate phase conjugate feedback from a BaTiO3 crystal. This research experimentally investigated the dynamics of a single-mode laser diode with weak phase conjugate feedback using both the self-pumped and double phase conjugate geometries. The experimental results validated a mathematical model which numerically evaluates the Lang-Kobayahsi coupled differential equations. The model simulated the nonlinear behavior of a …

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