Thermal Characterization of 1.3μm InAsP/InGaAsP Ridge Waveguide MQW Lasers Based on I-V Method

An experimental way for the thermal characterization of semiconductor lasers based on I-V method under pulse driving conditions has been developed, with which the thermal characteristics of strain compensated 1.3μm InAsP/InGaAsP ridge waveguide MQW laser chips have been investigated. The results show that, by measuring and analyzing the I-V characteristics under appropriate pulse driving conditions at different heat sink temperatures, the thermal resistance of the laser diodes could be easily deduced. The driving current and junction voltage waveforms of the laser chips under different pulse driving conditions are also discussed.     

Thermal Characteriztion of 1.3 μm InAsP／InGaAsP Ridge Waveguide MQW Laser Based on Spectroscopy Method

An experimental way to analyze the thermal characteriztion of semiconductor lasers based on spectroscopy method under pulse driving conditions has been developed,By using this way the thermal characteristicss of strain compensated 1.3 μm InAsP/InGaAsP ridge waveguide MQW laser diodes have been investigated.Results shovw that by measuring and analyzing the lasing spectra under appropriate driving parameters and temperature ranges,the thermal resistance of the laser diodes could be deduced easily,A higer thermal resistance of 640 K/W has been measured on a narrow ridge laser chip without soldering.Other thermal and spectral properties of the laser have also been measured and discussed.     

Transient Thermal Analysis of Ridge Waveguide InAsP／InGaAsP MQW Lasers Operating in Pulse Driving Conditions

The transient thermal characteristics of the ridge waveguide InAsP/lnGaAsP MQW lasers, especially in various pulse driving conditions, have been simulated by using FEM. The temperature at the active core of the laser versus the time has been calculated as well as pulse width dependence of the apparent thermal resistance. The results show that the thermal characteristics of the lasers are related to both the thermal conductivity and the specific heat of the materials.     

MBE-grown Ridge-waveguide InGaAs/InGaAsP Strained Quantum Well Lasers at 2 μm Wavelength

The result of molecular beam epitaxy (MBE)-grown ridge-waveguide InGaAs/ InGaAsP/InP strained quantum well lasers at 2 μm wavelength is reported. The pulsed electrical luminescence spectrum at room temperature is observed with peak wavelength of about 1.98 μm. At 77 K the lasers become lasing in pulse regime, with threshold current of about 18～30 mA, peak wavelength of about 1.87～ 1. 91 μm, and single longitudinal mode operation in the current range of 160～230 mA.     

LP-MOVPE生长的1.3μm InGaAsP/InP张压应变交替MQW特性

本文在国内首次报道了LP－MOVPE法生长高质量的压、张应变交替InGaAsP多量子阶结构的研制过程及其材料的高精度X射线双晶摇摆衍射曲线和光致发光谱特性表征．在此材料基础之上制作的平面掩埋条形结构激光器经过双腔面镀增透射膜后，其TE模与TM模自发发射谱光强差为3dBm，呈现偏振补偿特性．     

1.3μm低阈值InGaAsP/InP应变补偿MQW激光器的LP-MOCVD生长

报道了用低压金属有机物化学气相淀积（ＬＰ－ＭＯＣＶＤ）方法外延生长ＩｎＧａＡｓＰ／ＩｎＰ应变补偿多量子阱结构。用此材料制备的掩埋异质结（ＢＨ）条形结构多量子阱激光器具有极低阈值电流４～６ｍＡ。２０～４０℃时特征温度Ｔ０高达６７Ｋ，室温下外量子效率为０．３ｍＷ／ｍＡ。     

Effects of Non-abrupt Interface on Waveguide Properties of SiGe/Si MQW Photodetector

With the development of MBE and MOCVD techniques,the MQW waveguide has become an important structure in some optoelectronic devices[1~3].SiGe/SiMQW waveguide photodetectors have been demonstrated.By using the SiGe/Si MQW structures as natural waveguides,a high quantum efficie...     

键合方法研制InAsP/InGaAsP量子阱1.3μm垂直腔面发射激光器

设计并研制了由InAsP/InGaAsP应变补偿多量子阱有源层、SiO2/TiO2介质薄膜和GaAs/Al(Ga)As半导体分布布拉格反射镜(DBR)构成的垂直腔面发射激光器(VCSEL).采用直接键合技术实现InP基有源层与GaAs基DBR的晶片融合,并经过侧向湿法腐蚀定义电流限制孔径和沉积介质薄膜DBR等关键器件工艺,研制出InAsP/InGaAsP量子阱垂直腔面发射激光器,其阈值电流为13.5mA,单模激射波长为1288.6nm.     

键合方法研制InAsP/InGaAsP量子阱1.3μm垂直腔面发射激光器

设计并研制了由InAsP/InGaAsP应变补偿多量子阱有源层、SiO2/TiO2介质薄膜和GaAs/Al(Ga)As半导体分布布拉格反射镜（DBR）构成的垂直腔面发射激光器（VCSEL) . 采用直接键合技术实现InP基有源层与GaAs基DBR的晶片融合,并经过侧向湿法腐蚀定义电流限制孔径和沉积介质薄膜DBR等关键器件工艺,研制出InAsP/InGaAsP量子阱垂直腔面发射激光器,其阈值电流为13.5mA,单模激射波长为1288.6nm.     

Research and Porting of μC/GUI Based on μClinux

As μC/GUI occupies small memory and consumes low power,it has a wide range of applications.But it is little used in μClinux,because of being not give full play to its features.By the analysis of μC/GUI architecture structure and working principle,it improves μC/GUI,based on its work in the Framebuffer mode,so that μC/GUI functions and features give full play in μClinux.So it provides a more lightweight embedded GUI software for μClinux.The result shows that the working efficiency of μC/GUI has been improved greatly by using this method,even more than MiniGUI.     

Study of Photodiodes Based on the InGaAs Structure with a Boundary Wavelength of 2.06 μm

Journal of Communications Technology and Electronics - I–V characteristics and spectral photosensitivities of photodiodes based on epitaxially grown hydrides of metal-organic compounds...     

Photovoltaic Characterization and Electrochemical Impedance Spectroscopy Analysis of Dye-Sensitized Solar Cells Based on Composite TiO2–MWCNT Photoelectrodes

Dye-sensitized solar cells (DSSCs) use the effect of light on dye molecules to generate electricity through a photoelectrochemical mechanism. The aim of this study is to synthesize nanostructured DSSCs based on titania–multiwalled carbon nanotube (TiO₂–MWCNT) composite photoelectrodes and improve their performance and efficiency. DSSCs were fabricated based on single-layer TiO₂–MWCNT photoelectrodes with various weight percentages of multiwalled carbon nanotubes and bilayer TiO₂/TiO₂–2%MWCNT photoelectrodes. The microstructure and thickness of the anodic layers were characterized by field-emission scanning electron microscopy and optical microscopy. Also, to compare the conversion efficiency and determine the electron behavior in the electrical equivalent circuit of these cells, photovoltaic characterization and electrochemical impedance spectroscopy (EIS) analysis were used. The DSSC based on a single-layer TiO₂–2%MWCNT electrode, compared with other single-layer DSSCs in this study, had the highest conversion efficiency of 3.9% (for anodic layer thickness of 9 μm). The efficiency of the solar cell with the bilayer TiO₂/TiO₂–2%MWCNT photoelectrode, in comparison with the single-layer solar cell with the TiO₂–2%MWCNT electrode, showed a 23% increase from 4.33% to 5.35% (for anodic layer thickness of 18 μm). EIS analysis indicated that the charge-transport resistance of the DSSC based on the bilayer photoelectrode, in comparison with the single-layer TiO₂ and TiO₂–2%MWCNT solar cells, was decreased by 68% and 57%, respectively.     

On the high characteristic temperature of an InAs/GaAs/InGaAsP QD laser with an emission wavelength of ~1.5 μm on an InP substrate

We report on a study of lasers with an emission wavelength of about 1.5 μm and high temperature stability, synthesized on an InP (001) substrate. Self-organized InAs quantum dots capped with a thin GaAs layer are used as the active region of the laser. A quaternary InGaAsP solid solution with a band-gap width of 1.15 eV serves as the waveguide/matrix layer. A high characteristic temperature of the threshold current, T ₀ = 205 K, is reached in the temperature range 20–50°C in ridge-waveguide laser diodes. A correlation between the values of T ₀ and the band-gap width of the waveguide layers is found.     

Emission-Line Width and α-Factor of 850-nm Single-Mode Vertical-Cavity Surface-Emitting Lasers Based on InGaAs/AlGaAs Quantum Wells

The emission-line width for 850-nm single-mode vertical-cavity surface-emitting lasers based on InGaAs/AlGaAs quantum wells is studied. The width of the emission line for a laser with a 2-μm oxide current aperture attains it minimum (~110 MHz) at an output power of 0.8 mW. As the optical output power is further increased, anomalous broadening of the emission line is observed; this is apparently caused by an increase in the α-factor as a result of a decrease in the differential gain in the active region under conditions of increased concentration of charge carriers and of high internal optical losses in the microcavity. The α-factor is estimated using two independent methods.     

Light-Emitting Diodes Based on an Asymmetrical InAs/InAsSb/InAsSbP Double Heterostructure for CO2 (λ = 4.3 μm) and CO (λ = 4.7 μm) Detection

Semiconductors - Asymmetrical double InAs/InAsSb/InAsSbP heterostructures are grown by metalorganic vapor phase epitaxy. Two types (A and B) of light-emitting diodes with wavelengths of 4.1 and 4.7...     

Study of the Auger Recombination Energy Threshold in a Series of Waveguide Heterostructures with HgTe/Cd0.7Hg0.3Te QWs Near 14 μm

Semiconductors - Stimulated emission from a heterostructure with Hg0.903Cd0.097Te/Cd0.7Hg0.3Te quantum wells, placed in a waveguide layer of wide-gap CdHgTe, is obtained at wavelengths of...     

Quantum dot semiconductor lasers of the 1.3 μm wavelength range with high temperature stability of the lasing wavelength (0.2 nm/K)

Lasers that emit in the 1.3 μm wavelength range and include the active region based on InAs quantum dots were grown by the method of molecular-beam epitaxy and have been studied. The cavity includes a multilayer interference reflector, which brings about the fact that a large factor of optical confinement and low leakage losses are obtained only for the light propagating at some angle and, consequently, having a strictly definite wavelength. It is shown that, due to the use of such a waveguide structure, the temperature shift of the lasing wavelength is 0.2 nm/K, which is 2.5 times smaller than this shift in the lasers with quantum dots and with a conventional structure of the waveguide. The lasers with the stripe-contact width W = 10 μm exhibited the spatially single-mode emission, which verifies the advantages of the suggested nonconventional structure of the optical waveguide.

     

Barrier рBn-Structure Based on GaAsSb/AlAsSb/InAsSb for Detection of IR Radiation in the Spectral Range of 3.1–4.2 µm

Journal of Communications Technology and Electronics - In the study, a new рBn-architecture based on a GaAsSb/AlAsSb/InAsSb heterostructure of III‒V group materials with an...