A5101620572- Antenna Design and Analysis
- Microwave Engineering and Waveguides
- Semiconductor Lasers and Optical Devices
- Advanced Antenna and Metasurface Technologies
- Advanced Photonic Communication Systems
- Metamaterials and Metasurfaces Applications
- Laser Material Processing Techniques
- Optical Network Technologies
- GaN-based semiconductor devices and materials
- Millimeter-Wave Propagation and Modeling
- Advanced Optical Network Technologies
- Laser Design and Applications
- Semiconductor Quantum Structures and Devices
- Wireless Body Area Networks
- Semiconductor materials and devices
- Molecular Communication and Nanonetworks
- Surface Roughness and Optical Measurements
- Advancements in Semiconductor Devices and Circuit Design
- Thermal Radiation and Cooling Technologies
- Advanced Wireless Communication Technologies
- Advanced Surface Polishing Techniques
- Energy Harvesting in Wireless Networks
- Silicon Carbide Semiconductor Technologies
- Plasmonic and Surface Plasmon Research
- Modular Robots and Swarm Intelligence
Université du Québec en Abitibi-Témiscamingue
2023-2024
Lahore University of Management Sciences
2021
National University of Sciences and Technology
2014-2020
OSRAM (Germany)
2018-2019
Aalto University
2010-2011
City College of New York
1995
We present the design, construction and in vivo rabbit testing of a wirelessly powered contact lens display. The display consists an antenna, 500 × µm2 silicon power harvesting radio integrated circuit, metal interconnects, insulation layers 750 transparent sapphire chip containing custom-designed micro-light emitting diode with peak emission at 475 nm, all onto lens. can be from ∼1 m free space ∼2 cm on rabbit. was tested live, anesthetized rabbits no observed adverse effect. In order to...
A novel substrate integrated waveguide (SIW)-based leaky-wave antenna (LWA) is presented for backward endfire radiation and wide range scanning from to near broadside. Wide range, high gain, lower sidelobe levels are achieved by properly designing the radiating slots unit cell. The design provides measured (-90°) gain of 9.5 dBi at 16.7 GHz 17.4 19.8 GHz. Gain increases with frequency as beam begins move away broadside providing 80° range. Sidelobe return loss well below -10 dB. prototype...
The availability of high-power blue diode-lasers established a new class laser sources for materials processing recently. With the significantly shorter wavelength compared to conventional applications are moving into range feasible. There is strong demand welding with copper due change from internal combustion engines electric drives, which even prompts manufacturers find complex solutions obtain source in where shows higher absorption. appearance diode-laser bars range, proven optical...
More and more applications are using GaN laser diodes. Visible blue devices well established light sources for converter based business projection of several thousand Lumens. Additional laser-based concepts like near-to-eye push device requirements above heretofore limits. In 2017, threshold currents 10 20mA were reported single mode green laser, respectively. We will present a drastic reduction R&D samples by than factor 2 down to 10mA. also discuss turn-on delay as limiting modulation...
Industrial material processing like cutting or welding of metals is rather energy efficient using direct diode pumped solid state lasers. However, many applications cannot be addressed by established infrared laser technology due to fundamental properties the workpiece: For example materials copper gold have too low absorption in near wavelength range processed efficiently use existing high power systems. The huge interest enable kW systems with more suitable wavelengths blue spectral...
The performance of a gain-equalized, eight-wavelength WDM optical add-drop multiplexer (W-ADM) has been measured. By operating the EDFA 9-dB into saturation, gain was equalized to within 1 dB with minimum 15 dB, over 20-nm bandwidth and for total input signal power variations 8 dB. individual output powers were constant 6-dB range powers. These results indicate that large it would not be necessary readjust equalizer. However, pump degradation had stronger impact on variation: 1.4-dB...
With the advent of high power blue laser diodes in general and bars particular new applications are emerging, utilizing this technology. Possibly biggest benefits compared to traditional diode wavelengths infrared spectral range improvements seen copper welding applications, both weld quality overall process efficiency. A generation lasers with emission near 450 nm is being developed at Coherent DILAS. These modules achieve brightness levels combined power, suitable for materials processing...
Abstract Owing to its great potential in optoelectronic devices, a lot of effort has recently been put into improving the crystal quality heteroepitaxial GaN. In this study, GaN layers grown on patterned GaN/sapphire substrates are non‐destructively investigated by X‐ray diffraction techniques. The effect patterning is characterized determining strain and lattice tilt twist overgrown layers. High resolution (HRXRD) scans reciprocal space maps (RSMs) were utilized for purpose. Synchrotron...
In this paper, a new millimeter-wave (mmWave) co-planar waveguide (CPW) fed monopole antenna backed by artificial magnetic conductor (AMC) is presented. A novel AMC unit cell has been designed and 2×2 array used below the to increase gain achieve low specific absorption rate (SAR) values 1.6 W/Kg. Novelty of lies in fact that single or dual band operation can be achieved only adjusting inner patch size without changing outer dimensions cell. Presented zero reflection phase at 28GHz for...
WDM optical add-drop multiplexers (WDM-ADM) are of interest for the construction high capacity self-healing ring networks.1 A key technical problem is compensating wavelength-dependent gain erbium-doped fiber amplifiers (EDFAs), which will be needed to overcome losses WDM-ADM and attenuation between nodes on ring. Several solutions have been proposed nonflat EDFA gain, including use strongly inverted EDFAs,2 variable attenuators,3,4 gain-compensating filters consisting Mach-Zehnder...
We have applied positron annihilation spectroscopy to study 400 – 500 nm InGaN-based LED structures, as well InGaN and AlGaN materials with varying In Al contents. find that the effect of adding GaN on parameters obeys Vegard's law, while in case possible is completely screened by efficient formation cation vacancies. The results obtained structures are indistinguishable from defect-free GaN, suggesting positrons annihilate preferentially barriers MQW system.
A new substrate integrated waveguide (SIW) based leaky wave antenna (LWA) is presented in this paper for backward endfire (-90°) radiation. Measured gain at 12.1 dBi. To verify the simulated results, a prototype fabricated. The proposed well suited applications including unmanned aerial vehicles (UAVs), modern RADAR systems, directional communication missiles and self-driving cars etc.
Metasurfaces are planar versions of engineered materials which have interesting electromagnetic (EM) wave manipulation capabilities. Reconfigurable Intelligent Surfaces (RISs) run time programmable metasurfaces and being researched as 6G wireless communication enablers due to their dynamic EM response. We present an RIS fabrication strategy that can be used in lab settings for quickly prototyping realizing designs. demonstrated sample using dry etching well wet etching. Decision process...
In this paper, a high performance inversion type enhancement mode N-channel <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.65</sub> Ga xmlns:xlink="http://www.w3.org/1999/xlink">0.35</sub> As MOSFET has been presented. A maximum drain current of more than 1.3 A/mm achieved with transconductance 430 mS/mm. This value is nearly 25% greater that previously reported in literature. gate threshold voltage 0.8 V for length 0.6 μm, which sufficiently...