A5059172025- Photonic and Optical Devices
- Semiconductor Lasers and Optical Devices
- Silicon Carbide Semiconductor Technologies
- Semiconductor Quantum Structures and Devices
- Optical Network Technologies
- Space Exploration and Technology
- History and Developments in Astronomy
- Advanced Wireless Communication Technologies
- Radio Frequency Integrated Circuit Design
- GaN-based semiconductor devices and materials
- Advanced Materials and Mechanics
- Adaptive optics and wavefront sensing
- Modular Robots and Swarm Intelligence
- Spectroscopy and Laser Applications
- Advancements in Semiconductor Devices and Circuit Design
- Online and Blended Learning
- Superconducting and THz Device Technology
- Superconducting Materials and Applications
- Solid State Laser Technologies
- Photorefractive and Nonlinear Optics
- Antenna Design and Analysis
- Atomic and Subatomic Physics Research
- Glass properties and applications
- Nuclear Physics and Applications
- Advanced MIMO Systems Optimization
Huawei Technologies (Sweden)
2023-2024
The Evergreen State College
2016
Filtronic (United Kingdom)
2005-2006
Agilent Technologies (United Kingdom)
2002-2005
University of Strathclyde
1998-2005
Loma Linda University
2004
We report on actively stabilized single-frequency operation of a vertical-external-cavity surface-emitting semiconductor laser (VECSEL). The VECSEL was locked to 300-MHz reference cavity allowing relative frequency measurement that indicated linewidth 3 kHz. Coarse tuning over an 8.5-nm range achieved, with fine 250 MHz. produced up 42 mW output power in operation.
We report the development and characterization of an efficient diode-pumped surface-emitting semiconductor laser operating at approximately 870 nm. By using a Bragg reflector stack/multiple GaAs quantum well structure, mounted within conventional cavity, we achieved single transverse mode output powers 153 mW. Self-tuning over 15-nm spectral range has been obtained.
Combining an optimised active region based on InGaAsP strained MQW (multi quantum well) and a low parasitic lateral confinement region, we fabricated 10 Gb directly modulated uncooled DFB lasers which represent, believe, the state of art. Our work up to 100/spl deg/C (substrate base temperature) with eye diagram perfectly open (showing extinction ratio > 5 dB) bit error rate over km without floor. Up 90/spl our DFBs show threshold current as 29 mA. optical power high 13 mW meet scaled...
This letter presents a design of an electronically reconfigurable unit cell (UC), that can be used in the construction intelligent reflecting and refracting surfaces (IR <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> Ss) for future 6G communication. It independently perform beam forming or steering both reflection refraction modes. The IR S UC responds separately to TE TM incidences. utilizes PIN diodes obtain two phase states, 0° 180°...
This paper introduces a design for 1-bit reconfigurable Transmitted/Reflected Array (TRA), capable of electronic beamforming in both transmission and reflection. The TRA is constructed using the Unit Cells (UCs) that respond differently to TE TM incidences. By employing PIN diodes, UC achieves two phase states, 0° 180°, reflection, respectively. Simulation results show proposed has demonstrated independent control transmitted reflected beams at working frequency 5.9 GHz. A peak gain 18.1 dBi...
100/spl deg/C, 10 Gb/s operation has been demonstrated using conventional InGaAsP technology and a 'robust' design. The key results are:- excellent temperature performance, passing of the GbE scaled mask from RT to 90/spl deg/C transmission over km standard fibre without error floor.
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Summary form only given. Er/sup 3+/ has been shown to be a good rare-earth dopant of crystals and glasses for practical applications as laser-active media infrared-to-visible signal converters. In the present work we used low-temperature photoluminescence measurements in 4 300 K range study effects temperature on some radiative transitions lead-tellurium-germanate glass being developed fiber laser applications. The studied include green emission lines /sup 4/S/sub 5/2//spl rarr//sup 4/I/sub...
VCSELs based on InGaAs MQW structures are already being applied in pumping of erbium doped fibre amplifiers where high brightness beams advantageous for coupling into single mode fibres. Within this paper we will describe the first frequency operation a VECSEL GaAs structure operating around 870 nm. Such expected to be widespread use spectroscopic applications due their wavelength versatility, simplicity design and stable narrow linewidth operation.
This paper presents a simulation of the transient behavior filtronic SP6T switch. By employing non-linear switch model representation switching dynamics is presented. The simulations predict that changing control voltages has quickly attenuate fundamental power, however harmonic performance dependant on total bias applied to and hence relaxes its steady state condition 0.15mus after have settled. Within this we demonstrate importance understanding during transitions between equilibrium...
Summary form only given. Vertical external-cavity surface-emitting lasers (VECSELs) are attractive due to their potential for wavelength versatility, power scaling and spectrally/temporally controlled output. VECSELs based on InGaAs quantum wells with AlGaAs/GaAs Bragg reflectors have been employed in compact CW configurations pumping of erbium fiber amplifiers, intracavity absorption spectroscopy second-harmonic generation. Work employing GaAs well structures produce laser oscillation...
Surface emitting lasers with high output power in a single transverse mode have much potential for applications optical communications, laser printing and data storage. However, VCSEL’s been limited to 1-5mW although large aperture can provide they are highly multimode. Optically pumped external-cavity surface 1,2 overcome this limitation because the active region is defined by shape of pumping beam which be matched external cavity promote oscillation mode. Furthermore, operating an cavity,...