电极条形双区共腔半导体双稳态激光器静态和瞬态行为的精确理论计算

提出考虑到载流子侧向扩散分布以及光场模式分布精确描述具有非自建增益波导的电极条形双区共腔半导体双稳态激光器中物理过程的理论模型,从外加电极等势体出发对所涉及各种分布,不作任何人为假设,自洽地计算分析了半导体激光双稳态的静态特性和开关过程,并与现行集中均匀近似假设的计算结果进行比较,并指出其局限性。发现载流子侧向扩散分布和光场模式分布及其相互作用使激射阈值电流显著提高,双稳区宽度减小,开关时间加长。指出采用自建拆射率波导结构可明显改进双稳态性能。     

CCTS结构GaAs/AlGaAs单量子阱双稳态激光器

本文报道了CaAs/AlGaAs单量子阱(SQW)双区共腔(CCTS)结构的双稳态激光器,给出了增益区和吸收区分别注入电流时的三端器件结构。并在脉冲工作下得到了双稳特性。     

GaAs／GaAIAs多量子阱CCTS结构双稳态激光器的实验研究

本文报道了GaAs/GaAIAs多量子阱（MQW）双区共腔（CCTS）结构的双稳态激光器。该器件利用多次离子注入形成电镉离很好的双电极结构，吸收区上加上一定反偏压电压时得到了双稳特性，观察到了器件工作于双稳态时对光谱边模的显著抑制。     

InGaAsP单量子阱半导体微盘激光器研究

利用普通的液相外延和微加工技术成功地制备了ＩｎＧａＡｓＰ单量子陆微盘激光器，并从实验上观测到远低于普遍激光器阈值条件下的单模振荡，证实了微盘激光器中微盘很强的模式选择作用，反映了微盘的微腔特征。     

InGaAsP/InP CCTS双稳态激光器的纵模及偏振特性

本文给出了InGaAsP/InP CCTS双稳态激光器的模式特性。通过实验得到对双稳态激光器来说其吸收区的存在,使其对偏振及纵模的选择有一定的作用,使得TM模的输出强度在总输出中占的比例更小,及在双稳区内给出单纵模输出。     

半导体双稳态激光器在光注入下的实验研究

本文报道了InGaAsP/InP 双区共腔脊形波导双稳激光器在外光注入下产生光-光双稳特性及光-光放大的实验结果,给出了器件在直流及脉冲工作时的光-光双稳特性,并对结果进行了初步分析.     

InGaAsP／InP双区共腔激光器的内部参数

根据《双区半导体激光器的稳定性理论》,分析了 InGaAsp/Inp 掩埋异质结构双区共腔激光器的实验结果,计算了这种器件的内部参数。结果表明:内部光耦合随着温度变化是改变器件工作状态的主要因素;阈值电流偏高与器件工艺相关的界面缺陷、结构漏电关系极大;结构漏电可以提高光输出功率。     

分子束外延生长多量子阱激光器的实验研究

本文报道了GaAlAs/GaAs多量子阱激光器的实验结果。采用Zn扩散平面条形结构的6μm宽单条激光器,获得了线性输出功率大于100mW的良好结果,其阈值电流密度为2000A/cm~2,室温下特征温度大于400K。     

Temperature dependence of bistable InGaAsP/InP lasers

An increase of hysteresis current width in bistable lasers with two or three sections was observed at higher temperatures. A rate equation analysis was performed where both carrier density dependence on lifetime and the bleaching of saturable absorption by the spontaneous emission were taken into account. We show that the increased loss of injected carriers due to Auger recombination process causes the increase in the hysteresis width. A small-signal stability analysis for the switch-off point revealed that increased coupling between carriers in the gain and absorption regions, through the absorption of superradiant emission, has the effect of raising the switch-off point to higher current levels. It was shown experimentally that, without changing the temperature, the current hysteresis width can be controlled by adjusting the current distribution in three sections.     

Experimental and theoretical analysis of the carrier distributionin asymmetric multiple quantum-well InGaAsP lasers

The authors present an experimental and theoretical analysis of the carrier distribution in multiple quantum-well (MQW) lasers and the effect of this carrier distribution on the gain of wells at different locations in the active region. An experimental technique using mirror image asymmetric multiple quantum-well (AMQW) lasers is described which provides quantitative information on the degree to which the carrier distribution affects the gain of quantum wells (QWs) in the active region. A gain model for AMQW lasers is developed and used to explain some important characteristics of AMQW devices. A rate equation model is presented which incorporates the effects of fields across the p-i-n junction active region. The model is able to predict experimental results measured from thirteen AMQW laser structures to within experimental uncertainty     

Analysis and application of theoretical gain curves to the design of multi-quantum-well lasers

Gain/current curves for a single quantum well are calculated. The optimum well number, cavity length, threshold current, and current density of multi-quantum-well (MQW) lasers are derived in terms of this gain curve. The limiting performance of MQW lasers is found to be better than that of graded refractive index (GRIN) lasers, assuming comparable efficiencies and spontaneous emission linewidths. The optimum threshold current for an MQW laser with a 7 μm cavity and 90 percent facet reflectivity issim50 muA/μm.     

Millimetre-wave response of InGaAsP lasers

The intensity modulation response of 1.3 ?m-wavelength InGaAsP constricted-mesa lasers under pulsed operation is measured from 100 MHz to 40 GHz. 3 dB bandwidths of 25 GHz at 20°C and 31 GHz at ?40°C are observed.     

Strained InGaAsP multi-quantum-well structures for InP-based wide linewidth and polarization-insensitive semiconductor optical amplifiers

We have calculated the band structure of 1.55 μm InGaAsP/InGaAsP multi-quantum-well structures using Lüttinger–Kohn Hamiltonian taking into account the strain in the quantum wells (QWs) and barriers, and the confinement in the quantum wells. Using the calculated dispersion curves and oscillator strength between the different interband transitions, we have determined the optical gain in TE and TM mode and the spontaneous amplified emission as a function of injected carrier density in devices composed of quantum wells with different thicknesses. We find that an optical gain linewidth larger than 130 nm with a TE/TM polarization dependence lower than 1 dB can be obtained using a three-quantum-well In_0.53Ga_0.47As_0.96P_0.04/InGaAsP active layer with quantum well thicknesses of 10, 14 and 19 nm.     

Modeling and measurement of bistable semiconductor lasers

A theoretical model of bistable semiconductor lasers (BSL) under optical triggering is proposed, which takes into account the amplification and absorption processes in the laser structure. It has been found that the main factor limiting the highspeed operation of BSLs is the carrier lifetime in the absorber. A novel solution has been proposed consisting of bombarding the absorber with a proton beam. This paper presents the first experimental and theoretical results on the transition time and the turn-on jitter of such a BSL with optical triggering. Measurements on bulk and multiple quantum well BSLs revealed the dependence law of transition time and turn-on jitter on the injection currents. It has been found that, for a constant current in one active section, the rise time decreases but the fall time increases with injection current in the other section. An optimal current value can then be found to minimize the overall transition time. The measured turn-on jitter and relaxation oscillation period decrease with increasing injection current, in good agreement with theoretical predictions. 2.5 Gb/s optical triggering with a bit-error-rate less than 10^-9 is demonstrated, for the first time, by using such a BSL without electrical reset     

Integration of 1024 InGaAsP/InP optoelectronic bistable switches

A photonic parallel memory (PPM), which is an array of 32×32 optoelectronic bistable switches, is discussed. The switch consists of a heterojunction phototransistor (HPT) and a light-emitting diode (LED). Optical positive feedback from LED to HPT is the cause of bistability. The PPM can be written in and read out with 1-kb parallel optical signals. The PPM has been fabricated and memory operation has been demonstrated as expected. Dissipation current for a single switch and the input optical power necessary to turn on the switch were 600 μA and 20 μW, respectively. A light pulse with a width of 5 ns was able to turn on the switch, and the product of turn-on power and pulsewidth for the short pulse region was 1.5 pJ     

Intermodulation and harmonic distortion in InGaAsP lasers

A theoretical and experimental study is presented of intermodulation and harmonic distortion in high-speed 1.3 and 1.5 ?m InGaAsP lasers modulated at frequencies up to 8 GHz. It is found that all lasers measured, including Fabry-Perot and distributed feedback lasers, generate approximately the same distortion levels for a given modulation depth and relaxation resonance frequency. There are minor differences between lasers, which result from differences in the damping of the small-signal resonance peak.     

Theoretical and experimental study of threshold characteristics in InGaAsP/InP DH lasers

Threshold characteristics of stripe-geometry InGaAsP/InP double-heterostructure injection lasers have been analytically derived as a function of active layer thickness and stripe width. The effects of stripe width, refractive index in the active layer, diffusion of injected carriers, carrier lifetime, absorption loss in the cladding layer, gain coefficient, and cavity length on the optimum thickness of the active layer which gives minimum threshold or on threshold current density were studied. These lasers were fabricated on     

Experimental and theoretical characterization of the mode profile of single-mode DFB fiber lasers

The characterization of the spatial mode profile of distributed feedback fiber lasers (DFB-FLs) is discussed. A new approximate solution for the mode profile of single longitudinal mode DFB-FLs with nonuniform phase and grating profiles is derived. An enhanced high resolution heat perturbation method for mode shape characterization is described. Experimental mode shape profiles are compared with theoretical predictions with good agreement.