A5101556424- Semiconductor Quantum Structures and Devices
- Optical Network Technologies
- Advanced Fiber Laser Technologies
- Thermochemical Biomass Conversion Processes
- Quantum and electron transport phenomena
- Biofuel production and bioconversion
- Photonic and Optical Devices
- ZnO doping and properties
- Biodiesel Production and Applications
- Photonic Crystal and Fiber Optics
- Physics of Superconductivity and Magnetism
- Semiconductor Lasers and Optical Devices
- Advanced Semiconductor Detectors and Materials
- Advanced Fiber Optic Sensors
- Magneto-Optical Properties and Applications
- Electric Vehicles and Infrastructure
- Electronic and Structural Properties of Oxides
- Bioenergy crop production and management
- Advanced Combustion Engine Technologies
- Solid State Laser Technologies
- Neural Networks and Reservoir Computing
- Magnetic properties of thin films
- Advanced Photonic Communication Systems
- Seismic Performance and Analysis
- Enzyme-mediated dye degradation
Concordia College - Minnesota
2024
University of Florida
2017-2023
Oklahoma State University
2017-2022
University of Connecticut
2018-2022
Institute of Engineering
2022
Bowling Green State University
2016-2018
Eastern Illinois University
2014-2017
Clean Energy (United States)
2014-2017
Biomass gasification is a proven technology; however, one of the major obstacles in using product syngas for electric power generation and biofuels removal tar. The purpose this research was to develop evaluate effectiveness tar methods by cooling wood shavings as filtering media. performance filter equipped with an oil bubbler heat exchanger systems tested tar-laden generated from 20-kW downdraft gasifier. reduction efficiencies filter, exchanger, were 10%, 61%, 97%, respectively.
Near surface indium arsenide quantum wells have recently attracted a great deal of interest since they can be interfaced epitaxially with superconducting films and proven to robust platform for exploring mesoscopic topological superconductivity. In this work, we present magnetotransport properties two-dimensional electron gases confined an well near the surface. The mass extracted from envelope Shubnikov-de Haas oscillations shows average effective $m^{*}$ = 0.04 at low magnetic field....
The effect of two-photon absorption (TPA) on all-optical logic operation in quantum-dot semiconductor optical amplifier (QD-SOA) has been carried out. We model the rate equation with TPA for XOR gate, AND and, pseudo-random bit sequence (PRBS) generation. simulated results indicate that induced pumping increases output Q-factor (quality). show quality depends input pulse width and speed operation. PRBS system can operate at 250 320 Gb/s but an increase decreases Q-factor.
We perform a magneto-infrared spectroscopy study of the semiconductor to semimetal transition InAs/GaSb double quantum wells from normal inverted state. show that owing low carrier density our samples (approaching intrinsic limit), magneto-absorption spectra evolve single cyclotron resonance peak in state multiple absorption peaks with distinct magnetic field dependence. Using an eight-band Pidgeon-Brown model, we explain all major observed experiment. demonstrate can be realized by...
Recent progress of high-speed all-optical logic gates based on dual semiconductor optical amplifiers (SOAs) has been reviewed in this article. These schemes include using quantum-dot amplifier (QD-SOA) and two-photon absorption (TPA). Numerical simulation method was presented by solving the rate equations gain dynamics SOA. Performance operation is discussed calculating quality factor plotting eye diagram. Results show that SOA scheme a promising for realization systems future.
We present experimental and theoretical studies of the magneto-optical properties $n$-type ${\mathrm{InAs}}_{x}{\mathrm{P}}_{1\ensuremath{-}x}$ films in ultrahigh magnetic fields at room temperature. compare Landau level band structure calculations with observed cyclotron resonance (CR) measurements extract effective $g$-factors CR masses for two different alloy concentrations, $x=0.07$ $x=0.34$. In addition, we employ time-resolved Kerr on these ternary alloys to explore spin relaxation...
We propose a scheme to realize all-optical logic operation in quantum-dot semiconductor optical amplifier (QD-SOA) based Mach-Zehnder interferometer (MZI) considering the effects of two-photon absorption (TPA). During propagation sub-picosecond pulses QD-SOA, TPA leads an additional change carrier recovery dynamics quantum-dots. utilize rate equation model take into account refill through and nonlinear including heating spectral hole burning QD-SOA. The simulation results show induced...
Optically pumped NMR (OPNMR) of the NMR-active $^{69/71}\mathrm{Ga}$ species has been shown to be a unique method probe electronic energy bands in GaAs, with sensitivity light hole--to--conduction band transition. This transition is often obscured other optical measurements such as magnetoabsorption. Using OPNMR, we exploit hyperfine interaction between conduction electrons (and their spin states) and nuclear spins, which are detected through phase-sensitive radio-frequency (NMR)...
Using a two-color time-resolved pump-probe spectroscopy scheme, we studied the generation and detection of longitudinal coherent acoustic phonons, generated by ultrafast laser pulses in semiconductor heterostructure. Our structure was $p$-doped, 100-nm-thick ferromagnetic GaMnAs layer grown on GaAs substrate. By probing transient reflectivity time domain, observed strong dependence phonon's amplitude external magnetic field. theoretical model relates this to increase detectability phonons...
This study compares the gas sensing performance of ZnO and 5 % Fe-doped (Fe-ZnO) films synthesized by a spin coating technique.The XRD analysis unveiled polycrystalline nature initially prepared films, showing decrease in crystallite size from 25.69 ± 0.95 nm for to 19.49 0.72 Fe-ZnO.Furthermore, introduction Fe into increased band gap, with values shifting 3.190 0.105 eV 3.244 0.147 Fe-ZnO decreased grain sizes.The reduced sizes helped increase response film.The ethanol vapor experiments...
We report on the observation of an unusual negative magnetic hysteresis loop in ZnO thin film codoped with cobalt and aluminum (Co-Al:ZnO), while other transition-metal-doped films, such as Cu-doped Mn-doped ZnO, exhibit normal loops. The behavior is ascribed to presence double layers different moments due change structural defects across layers. Positron annihilation measurements confirmed unique microstructural changes Co-Al:ZnO film. This study shows that diluted semiconductors may induce...
In this paper, we propose and experimentally demonstrate a mode locked fiber ring laser with the implementation of photonic crystal (PCF) to generate pulse train at high speed. This combines rational harmonic locking based on Lithium Niobate Mach-Zehnder modulator nonlinear polarization rotation from highly PCF. By fine tuning modulation frequency controllers in cavity, 30 GHz width 1.9 ps is generated. Without PCF, 5.8 ps. We also conduct numerical simulations evolution, which shows good...
Mode locked fiber ring laser using graphene nanoparticles as saturable absorbers to compress the pulse width has been studied. An experimental method demonstrate generation of train with 50 GHz repetition rate an ultrashort demonstrated. This uses a combination rational harmonic mode-locking (RHML) and absorber in laser. The is shorter by about factor 2 compared that without absorber. Pulse analyzed. results are agreement from simulation.