HIGH-POWER 2-DIMENSIONAL QUANTUM-WIRE LASER ARRAYS

GaAs/AIGaAs two-dimensional quantum-well wire laser arrays fabricated by metal-organic chemical vapour deposition on nonplanar substrates have realised a linear light pulse output Fewer of over 100mW. This is the highest figure reported to date for all kinds of quantum-well wire lasers.

Narrow-beam divergence 1.55μm laser diodes with integrated self-aligned spotsize conVerter

This paper describes the high performance of narrow-beam divergence spot size converter (SSC) integrated separately confined heterostructure (SCH) LD. The upper optical confinement layer (OCL) and the butt-coupled tapered thickness waveguide were regrown simultaneously, which not only offered the separated optimization of the active region and the integrated spotsize converter, but also reduced the difficulty of the butt-joint selective regrowth. The threshold current was as low as 5.4 mA, the output power at 55 mA was 10.1 mW, the vertical and horizontal far field divergence angles were as low as 9°and 15°, and the 1-dB misalignment tolerances were 3.6 and 3.4μm, respectively.

Self-aligned Coupled Waveguide Distributed Bragg Reflector Lasers

A novel self-aligned coupled waveguide (SACW) multi-quantum-well (MQW) distributed Bragg reflector (DBR) laser is proposed and demonstrated for the first time. By selectively removing the MQW layer and leaving the low SCH/SACW layer the Bragg grating is partially formed on this layer. By optimizing the thickness of the low SCH/SACW layer, a ～80% coupling efficiency between the MQW gain region and the passive region are obtained. The typical threshold current of the SACW DBR laser is 39 mA, the slope efficiency can reach to 0.2 mW/mA and the output power is more than 20 mW with a more than 30dB side mode suppression ratio.

1.5μm Self-Aligned Spotsize Converter Integrated DFB Fabricated by Selective Area Grown MOVPE

High performance 1.57μm spotsize converter monolithically integrated DFB is fabricated by the technique of self-aligned selective area growth. The upper optical confinement layer and the butt-coupled tapered thickness waveguide are regrown simultaneously, which not only offeres the separated optimization of the active region and the integrated spotsize converter, but also reduces the difficulty of the butt-joint selective regrowth. The threshold current is as low as 4.4mA. The output power at 49mA is 10.1mW. The side mode suppression ratio (SMSR) is 33.2dB. The vertical and horizontal far field divergence angles are as small as 9° and 15° respectively, the 1dB misalignment tolerance are 3.6μm and 3.4μm.

Multiple Quantum Well SEED Arrays for Flip-Chip Bonding Optoelectronic Smart Pixels

于2010-11-23批量导入

Application of Wet Chemical Etching in Fabrication Process of GaAs/AlGaAs Quantum Dot Arrays

于2010-11-23批量导入

Two-dimensional quantum well wire semiconductor laser arrays

于2010-11-23批量导入

Optical analysis of AlGaInP laser diodes with real refractive index guided self-aligned structure

Optical modes of AlGaInP laser diodes with real refractive index guided self-aligned (RISA) structure were analyzed theoretically on the basis of two-dimension semivectorial finite-difference methods (SV-FDMs) and the computed simulation results were presented. The eigenvalue and eigenfunction of this two-dimension waveguide were obtained and the dependence of the confinement factor and beam divergence angles in the direction of parallel and perpendicular to the pn junction on the structure parameters such as the number of quantum wells, the Al composition of the cladding layers, the ridge width, the waveguide thickness and the residual thickness of the upper P-cladding layer were investigated. The results can provide optimized structure parameters and help us design and fabricate high performance AlGaInP laser diodes with a low beam aspect ratio required for optical storage applications.

Photoluminescence characteristics of GaAs/AlGaAs quantum dot arrays fabricated by dry and dry-wet etching

GaAs/AlGaAs quantum dot arrays with different dot sizes made by different fabrication processes were studied in this work. In comparison with the reference quantum well, photoluminescence (PL) spectra from the samples at low temperature have demonstrated that PL peak positions shift to higher energy side due to quantization confinement effects and the blue-shift increases with decreasing dot size, PL linewidths are broadened and intensities are much reduced. It is also found that wet chemical etching after reactive ion etching can improve optical properties of the quantum dot arrays.

Symmetry in the diagonal self-assembled InAs quantum wire arrays on InP substrate

Diagonal self-assembled InAs quantum wire (QWR) arrays with the stacked InAs/In0.52Al0.48As structure are grown on InP substrates, which are (001)-oriented and misoriented by 6degrees towards the [100] direction. Both the molecular beam epitaxy (MBE) and migration enhanced epitaxy (MEE) techniques are employed. Transmission electron microscopy reveals that whether a diagonal InAs QWR array of the stacked InAs/InAlAs is symmetrical about the growth direction or not depends on the growth method as well as substrate orientation. Asymmetry in the diagonal MEE-grown InAs QWR array can be ascribed to the influence of surface reconstruction on upward migration of adatoms during the self-assembly of the InAs quantum wires.

Hybrid waveguide-plasmon resonances in gold pillar arrays on top of a dielectric waveguide

We propose a hybrid waveguide-plasmon system consisting of gold pillar arrays on top of a dielectric waveguide. The formation of extraordinary transmissions induced by the hybrid waveguide-plasmon resonances is investigated by rigorous coupled-wave analysis. The characteristics of the hybrid resonances can be predicted by introducing the photonic crystal slab theory. Extremely narrow absorption peaks and the electromagnetically induced transparency-like optical property are demonstrated in our hybrid system. (C) 2010 Optical Society of America

Analysis of leakage current in GaAs micro-solar cell arrays

The output characteristics of micro-solar cell arrays are analyzed on the basis of a modified model in which the shunt resistance between cell lines results in current leakage. The modification mainly consists of adding a shunt resistor network to the traditional model. The obtained results agree well with the reported experimental results. The calculation results demonstrate that leakage current in substrate affects seriously the performance of GaAs micro- solar cell arrays. The performance of arrays can be improved by reducing the number of cells per line. In addition, at a certain level of integration, an appropriate space occupancy rate of the single cell is recommended for ensuring high open circuit voltages, and it is more appropriate to set the rates at 80%-90% through the calculation.

Surface Plasmon Resonances of Cu Nanowire Arrays

Surface plasmon resonances of arrays of parallel copper nanowires, embedded in ion track-etched polycarbonate membranes, were investigated by systematic changes of nanowires’ topology and arrays area density. The extinction spectra exhibit two peaks which are attributed to interband transitions of Cu bulk metal and to a dipolar surface plasmon resonance, respectively. The resonances were investigated as a function of wire diameter and length, mean distance between adjacent wires, and angle of incidence of the light field with respect to the long wire axis. The dipolar peak shifts to larger wavelengths with increasing diameter and length, and diminishing mean distance between adjacent wires. Additionally, the shape effect on the dipolar peak is investigated.

Synthesis and field emission of diamond-like carbon nanorods on TiO2/Ti nanotube arrays

Highly ordered TiO2/Ti nanotube arrays were fabricated by anodic oxidation method in 0.5 wt% HF. Using prepared TiO2/Ti nanotube arrays deposited Ni nanoparticles as substrate, high quality diamond-like carbon nanorods (DLCNRs) were synthesized by a conventional method of chemical vapor deposition at 750 degrees C in nitrogen atmosphere. DLCNRs were analyzed by filed emission scanning electron microscopy and Raman spectrometer. It is very interesting that DLCNRs possess pagoda shape with the length of 3-10 mu m. Raman spectra show two strong peaks about 1332 cm (1) and 1598 cm (1), indicating the formation of diamond-like carbon. The field emission measurements suggest that DLCNRs/TiO2/Ti has excellent field emission properties, a low turn-on field about 3.0 V/mu m, no evident decay at 3.4 mA/cm(2) in 480 min. (C) 2009 Elsevier B. V. All rights reserved.