A5080681522- Silicon Nanostructures and Photoluminescence
- Nanowire Synthesis and Applications
- Photonic and Optical Devices
- Optical Network Technologies
- Semiconductor Lasers and Optical Devices
- Luminescence Properties of Advanced Materials
- Semiconductor materials and devices
- Photonic Crystals and Applications
- Photonic Crystal and Fiber Optics
- Advanced Fiber Optic Sensors
- Thin-Film Transistor Technologies
- Advanced Fiber Laser Technologies
- Quantum Dots Synthesis And Properties
- Semiconductor materials and interfaces
- Mechanical and Optical Resonators
- Glass properties and applications
- Copper-based nanomaterials and applications
- Solid State Laser Technologies
- Laser Material Processing Techniques
- Microwave Dielectric Ceramics Synthesis
- ZnO doping and properties
- Advanced Photonic Communication Systems
- Silicon and Solar Cell Technologies
- Ion-surface interactions and analysis
- Photorefractive and Nonlinear Optics
Muscat College
2020
University College London
1997-2004
Alcatel Lucent (Germany)
2001
We develop a model for the excitation of erbium ions in erbium-doped silicon nanocrystals via coupling from confined excitons generated within nanoclusters. The provides phenomenological picture exchange mechanism and allows us to evaluate an effective absorption cross section up 7.3×10−17 cm2: four orders magnitude higher than stoichiometric silica. address origin 1.6 eV emission band associated with nanoclusters determine sections excitonic lifetimes silica which are order 1.02×10−16 cm2...
Silica thin films containing Si nanocrystals and Er3+ were prepared by ion implantation. Excess concentrations ranged from 5% to 15%; concentration for all samples was 0.5%. Samples exhibited photoluminescence at 742 nm (attributed nanocrystals), 654 (defects due implantation), 1.53 μm (intra-4f transitions). Photoluminescence intensity increased ten times incorporating nanocrystals. Strong, broad observed λPump away absorption peaks, implying energy transfer Erbium fluorescence lifetime...
We present a single-frequency, single-mode, plane-polarized ytterbium-doped all-fiber master oscillator power amplifier source at 1060 nm generating 264 W of continuous-wave output power. The final-stage operated with high gain 19 dB and conversion efficiency 68%. There was no evidence rollover from stimulated Brillouin scattering even the highest power, maximum limited only by available pump
University–industry (U–I) interactions are increasingly seen as critical components of national innovation systems and for building knowledge economies in developed developing countries alike. Considering the Triple Helix (TH) model university–business cooperation framework, we report results a study on current state barriers to U–I Oman. The is based qualitative review published higher education institute (HEI) quality audit reports questionnaire surveys HEIs industry. It suggested that...
Er/sup 3+/-doped tellurite and alumina optical waveguide amplifiers are analyzed both as single elements of 16-channel wavelength-division multiplexing (WDM) systems; their performances compared with that from Al/P silica amplifiers. The amplifier model is based on propagation population-rate equations includes uniform pair-induced up-conversion mechanisms. It solved numerically by combining finite the Runge-Kutta algorithm. analysis predicts waveguides exhibit improved gain characteristics...
We report the first deposition of Er/sup 3+/-doped aluminum oxide thin-film optical waveguides by plasma-enhanced chemical vapor (PECVD). The and erbium precursors used for thin films were trimethyl-aluminum Er tri-chelate 2,2,6,6-tetramethylheptane-3,5 dione respectively. samples show broad, room-temperature photoluminescence at /spl lambda/=1.533 mu/m. 3+/ concentration ranged from 0.01-0.2 at%. full width half maximum (FWHM) emission spectrum is 55 nm, considerably broader than in silica...
Small-signal amplification in short, Yb/sup 3+/-sensitized, Er/sup 3+/-doped alumina (Al/sub 2/O/sub 3/) channel optical waveguides with high 3+/ concentrations is analyzed. Taking into account uniform up conversion, excited state absorption (ESA) from the metastable level (/sup 4/I/sub 13/2/), and 3+//spl rarr/Er/sup energy transfer by cross relaxation, obtainable gain improvements compared to 3+/-free Al/sub 3/ are investigated. The amplifier model based on propagation population rate...
We discuss the dramatic development of high-power fiber laser technology in recent years and prospects kilowattclass single-frequency sources. describe experimental results from an ytterbium-doped fiber-based multihundred-watt single-frequency, single-mode, plane-polarized master-oscillator power amplifier (MOPA) operating at 1060 nm a similar source with 0.5 kW output power, albeit degraded beam quality (M<sup>2</sup> = 1.6) not linearly polarized. Experiments simulations aimed predicting...
Tapering of fused silica optical fiber using a carbon dioxide (CO2) laser as the heating source is analyzed taking into account Gaussian profile for power distribution. The differential thermal equation solved numerically an implicit Crank-Nicolson finite difference method. interaction CO2 electromagnetic (EM) radiation with treated Mie theory following approach plane-wave light scattering from thin rods. surface temperature studied function diameter and power. effect different EM...
Successful incorporation of both erbium and ytterbium in alumina by ion implantation is reported. Some evidence for indirect pumping through the transfer energy from has been observed. Both plasma-enhanced CVD deposited thin films sapphire crystals were employed as substrates. Yb3+ Er3+ concentrations ranged 2.4 At% to 8 0.4 0.8 At%, respectively. The samples show strong, broad, room-temperature photoluminescence at λ = 1.53 µm corresponding intra-4f transitions between 4I13/2 (first...
We report the observation of near-IR emission from erbium in silicon-rich silica, excited using a filtered white-light source. The characteristic I13/24–4I15/2 intra-4f transition at 1535 nm is observed even when excitation wavelengths corresponding to principal optical absorption bands are removed selective filtering. ascribe this effect an efficient transfer mechanism between silicon nanoclusters present silica films and rare-earth ions. This good agreement with our previous work area...
Experimental evidence of an efficient broadband sensitization mechanism in erbium-implanted alumina is presented. Alumina thin films were deposited by plasma-enhanced chemical vapor deposition using trimethyl-amine alane and nitrous oxide. The as-grown films, together with sapphire crystals, implanted erbium. Photoluminescence excitation spectra showed that crystals exhibit characteristic Er3+ luminescence at 1.53μm only when pumped resonantly. In contrast, even wavelengths outside...
A 16-channel, 2.5 Gb/s, wavelength-division multiplexing system is analyzed with its channels allocated in the 1.52-1.56 w m wavelength region order to increase usable amplifier bandwidth , 45 nm. To avoid amplified spontaneous emission (ASE) noise and nonuniform signal gain region, an module consisting of Er 3+ -doped tellurite waveguide amplifier, ASE filter, two concatenated long-period grating filters are proposed. tellurite-based was chosen as amplifying element because broad (~80 nm),...
We present a theoretical model of loss-compensated symmetric Y-junction acting as an optical beam splitter. consider silica (SiO/sub 2/) channel waveguides which are assumed to be highly doped with Er/sup 3+/. The was developed using the propagation method (BPM) and fast-Fourier-transform (FFT)-based algorithm. analysis showed that considerable gain levels, about 4.2 dB/cm at each port Y-junction, can achieved for erbium concentration 2.5/spl times/10/sup 20/ ions/cm/sup 3/, signal power 1...
Coupling between silicon nanoclusters and erbium ions n silicon-rich silica hosts can enhance the technologically important 4f emission at 1535nm relax restrictions on pump wavelength. We presents luminescence results showing that enhancement of absorption cross-section due to presence be around 4 orders magnitude. Temperature quenching in this material is very weak, indicating Auger non-radiative decay channels which limit bulk are largely absent silica. also demonstrate broad-band...
Abstract We report recent results showing broad‐band excitation of erbium ions implanted into thin films silica containing silicon nanoclusters. Indirect the rare‐earth is mediated by nanoclusters, which are either grown in during plasma‐enhanced chemical vapour deposition films, or formed implantation thermally SiO 2 layers with Si + ions. demonstrate efficient flashlamp pumping 1535 µm photoluminescence band and discuss device implications this material. Copyright © 2001 John Wiley & Sons, Ltd.
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Si nanocrystals (nc-Si) embedded in silica have recently attracted a lot of attention as potential optoelectronic material due to their light emission at approximately 1.7 eV. Er<SUP>3+</SUP> is attractive because its 1.53 micrometers coincides with the low attenuation region optical fibers. In this paper, we report experimental investigation energy transfer between nc-Si and ion implanted which may relax requirements on pump source lead broad-band pumped devices.