耦合垂直腔面发射激光器的阈值及输出特性

针对耦合垂直腔面发射激光器,利用边界条件,结合激光器的中间DBR层的耦合传输矩阵,推导出了不同激射波长工作时,两腔内光场应满足的方程,由此得到两腔光子之间的耦合因子,然后结合稳态载流子速率方程,按照激射波长,得出了器件的四种工作状态,并详细地讨论了顶腔和底腔注入电流对器件输出特性的影响.     

Ultralow Threshold Lasing in InGaAs/InGaAs PMQ WMicrodisk Laser

Ｗｉｔｈｔｈｅａｄｖａｎｃｅｏｆｓｅｍｉｃｏｎｄｕｃｔｏｒｎａｎｏｆａｂｒｉｃａｔｉｏｎｔｅｃｈｎｉｑｕｅａｎｄｔｈｅｎｅｅｄｆｏｒｕｌｔｒａ－ｌａｒｇｅｓｃａｌｅｉｎｔｅｇｒａｔｅｄｏｐｔｉｃａｌｅｌｅｃｔｒｏｎｉｃｄｅｖｉｃｅｓ,ｍｉｃｒｏｃａｖ...     

基于半导体光放大器的可调谐环形腔激光器的激光建立过程

基于半导体光放大器(SOA)的环形腔激光器可实现高达兆赫兹的高速调谐,在光纤通信和光纤传感领域有广泛应用。采用稳态模型和分段算法研究SOA自发辐射特性,并基于此分别讨论了使用高斯型滤波器和法布里-珀罗(F-P)滤波器的两种可调谐环形腔激光器,研究了激光建立过程的特性,包括输出光谱和输出光功率随绕行圈数的变化,讨论了波长调谐的速度。结果表明,F-P滤波器的环形腔可以更快建立激光振荡,便于实际高速调谐应用。     

半导体激光器列阵的电导数及其可靠性

在研究半导体激光器电导数与可靠性的基础上,设计了单管激光器并联实验系统,利用单管激光器并联模拟列阵的方法研究了激光器列阵的可靠性在其电导数曲线和参数上的体现,该实验结果为利用电导数参数作为列阵可靠性判据提供了参考.     

半导体微腔激光器阈值特性分析

利用速率方程理论讨论了半导体微腔激光器的激射阈值与自发发射耦合系数β之间的关系,分析了降低阈值的途径,为器件设计提供了依据。     

InGaAs/GaAs量子点类脊型激光器的激射特性

用MOCVD方法生长制备了多层InGaAs/GaAs量子点结构 ,并研制出量子点激光器。研究了多层量子点激光器阈值激射特性与量子点有源区结构之间的关系 ,结果表明激光器的阈值电流密度依赖于量子点的结构。通过采用多层量子点、对量子点层间进行耦合以及采用宽禁带AlGaAs作为量子点层势垒可以有效地降低激光器的阈值电流密度。获得了最低为 2 0A/cm2 的平均阈值电流密度。量子点激光器的激射波长也与有源区结构有关 ,随着量子点层数增加 ,激射峰向长波方向移动。     

半导体环形激光器的输出耦合及阈值增益分析

通过三维光波导的模式耦合理论分析了半导体环形激光器(SRL)与直波导的耦合系数,用耦合系数的解析表达式结合SRL自再现条件分析了SRL各参数对阈值增益的影响.分析结果表明,耦合系数随波导宽度和厚度、波导间距的增大而减小,随SRL半径的增大而增大;阈值增益随波导宽度和厚度、波导间距的增大而增大,随SRL半径的增大而减小.     

半导体激光器光束特性的研究

研究半导体激光器(LD)的光束特性,并对其远场图像是近场图像的傅里叶变换进行了分析和推导。半导体激光器输出光束的方向性很差,发散角大致为10°-40°,并且在快轴和慢轴两个方向上相差较大,使得半导体激光器发射的激光束的束斑呈椭圆状,这对长距离传输很不利,因此本文还研究了光束的准直技术。     

重频激光辐照半导体损伤的有限元分析

在考虑到材料热力学参数随温度变化的前提下,以热传导方程和热弹方程为基础,采用有限元分析算法,考查了200ns脉宽、1064nm波长重频激光辐照下,半导体材料InSb体内的温升和热应力分布,分析了由温升效应所致该材料的损伤破坏类型,探讨了热熔融损伤和热应力损伤阈值随光斑尺寸、脉宽、重复率、脉冲次数等的变化规律。     

A Vertical-Cavity Surface-Emitting Laser at Threshold

Linewidth is measured over the threshold transition of a vertical-cavity surface-emitting laser and results are compared to a FokkerPlanck semiconductor laser model. The linewidth shows nonmonotonous behavior at threshold similar to that previously observed in distributed feedback lasers. The behavior agrees with the FokkerPlanck model if the linewidth enhancement factor $alpha approx 5.0$. Measurement of the relaxation oscillation frequency and the damping rate using an injected optical probe allows, together with the FokkerPlanck model, the extraction of major laser parameters.      

980nm半导体激光二极管的温度特性

测试并分析了980nm半导体激光二极管( SLD)模块的输出光功率、光谱和消光比与注入电流及温度的变化关系。结果反映:在测试范围内,温度不变时该模块的输出光功率随注入电流的增大而增加,经历了自发辐射和受激放大过程;电流不变时该输出光功率随管芯温度的变化基本保持稳定。温度不变的情况下,当注入电流小于阈值电流时,峰值波长、3dB带宽和消光比随注入电流的增大而较快增加,当注入电流大于阈值电流时,峰值波长、3dB带宽和消光比随注入电流的增大而缓慢增加;电流不变时峰值长、3dB带宽和消光比随温度升高而有所增大。     

连续工作的体布拉格光栅外腔半导体激光器的温度特性

对体布拉格光栅(VBG)作为波长选择元件的外腔半导体激光器的波长锁定进行了实验研究,报道了连续运转输出功率达43.5 W的半导体激光器阵列的体布拉格光栅波长锁定实验结果,给出了不同热沉温度下的稳定的波长锁定结果,说明采用体布拉格光栅外腔将减小半导体激光器的温控压力。实验中发现,随着注入电流的增大,输出激光功率逐渐增强,锁定的激射波长向长波长方向偏移。在输出功率为34.5 W时,波长红移约0.56 nm。这一移动与实验测量的体布拉格光栅的温度特性相吻合。连续和高占空比运行、高输出功率情况下,在器件的设计和使用时应该考虑这一效应。     

Threshold Current Characteristics of Intracavity-contacted Vertical-cavity Surface-emitting Laser

Threshold current characteristics of intracavity-contacted oxide-confined vertical-cavity surface-emitting laser had been investigated in detail. Threshold current characteristics not only were depended on the size of oxide-aperture, but also were also strongly affected by the mismatch of its lasing mode and gain peak. For the same degree detuning of the gain peak and lasing mode at room temperature, the threshold current was approximately proportional to the square of the oxide-aperture diameter of above 5μm. For the same oxide-aperture device, the larger the detuning degree of the lasing mode shifted to the shorter wavelength of the gain peak at room temperature was, the lower the minimum threshold current was. The wavelengths of the lasing mode and gain peak were ±N×10nm detuning at 300K, The temperature of the minimum threshold current was changed to be about ±N×40K(N real number). The calculated results were consistent with the experimental ones.     

Manipulable and Hybridized,Ultralow‐Threshold Lasing in a Plasmonic Laser Using Elliptical InGaN/GaN Nanorods

Manipulating stimulated‐emission light in nanophotonic devices on scales smaller than their emission wavelengths to meet the requirements for optoelectronic integrations is a challenging but important step. Surface plasmon polaritons (SPPs) are one of the most promising candidates for sub‐wavelength optical confinement. In this study, based on the principle of surface plasmon amplification by the stimulated emission of radiation (SPASER), III‐Nitride‐based plasmonic nanolaser with hybrid metal–oxide–semiconductor (MOS) structures is designed. Using geometrically elliptical nanostructures fabricated by nanoimprint lithography, elliptical nanolasers able to demonstrate single‐mode and multimode lasing with an optical pumping power density as low as 0.3 kW cm^?2 at room temperature and a quality Q factor of up to 123 at a wavelength of ≈490 nm are achieved. The ultralow lasing threshold is attributed to the SPP‐coupling‐induced strong electric‐field‐confinement in the elliptical MOS structures. In accordance with the theoretical and experimental results, the size and shape of the nanorod are the keys for manipulating hybridization of the plasmonic and photonic lasing modes in the SPASER. This finding provides innovative insight that will contribute to realizing a new generation of optoelectronic and information devices.     

半导体激光器模分配特性的研究

本文分析了半导体激光器模分配特性对光纤传输系统的影响,给出了模分配系数K的物理意义,计算了在不同误码率底线、不同波动程度、不同波长和不同的光源频谱下的系统传输速率和传输距离以及相应的功率代价。     

Spontaneous Emission and Lasing of a Two-Wavelength Quantum-Cascade Laser

Semiconductors - The results of experiments on the fabrication (by molecular-beam epitaxy) and investigation of the heterostructures of a two-frequency quantum-cascade laser produced on the basis...     

微碟激光器的单模低阈值激射

简单分析了碟型微腔激光器中的激射模式及自发发射系数。采用反应离子刻蚀和选择性刻蚀方法蚀刻出InGaAs InGaAsP多量子阱 (MQW)碟型激光器 ,碟直径 3 μm ,在液氮温度下进行光抽运实验 ,观察其模式特性。实现了单模激射 ,波长 1 5 μm ,抽运阈值 18μW。     

GaN基和GaAs基半导体激光器的电学特性研究

介绍了一种能够全面表征半导体二极管器件的电学特性的方法,此方法结合半导体二极管的正向交流特性和直流特性,称之为正向交流小信号法。利用该方法深入地研究和对比分析了GaN基和GaAs基半导体激光器的电学特性,包括表观电容、串联电阻和理想因子。实验结果表明,对于GaN基和GaAs基半导体激光器,其开始发光的过程同步于其电容由正转变为负的过程。进一步实验结果表明,GaN基半导体激光器比GaAs基半导体激光器具有更大的串联电阻和更大的理想因子。这是由于GaN基激光器的器件工艺不够完善以及外延生长的GaN材料具有很大的位错密度。该研究为提高和改善GaN基激光器的性能提供了必要的依据以及理论指导。     

Competition of Rational Harmonic Mode-Locking and Continuous-Wave Lasing in Semiconductor Optical Amplifier Fiber Laser Under Optical Pulse Injection

Twentieth-order rational harmonic mode-locking (RHML) semiconductor optical amplifier fiber laser (SOAFL) pulses are demonstrated by using 1-GHz backward dark-optical comb injection. Maximum frequency detuning range of plusmn 300 Hz, broadened pulsewidth of 35 ps, and highest average power of 0.4 muW for twentieth-order RHML-SOAFL pulse are characterized. The extraordinary phenomena on the red-shifted wavelength from 1535.5 to 1541.5 nm and the corresponding spectral linewidth reduced from 12 to 3 nm are observed with the RHML order increasing to 8 or higher. Such a less pronounced RHML mechanism at higher orders occurred in the optically injection mode-locked SOAFL is mainly attributed to the weak mode-locking strength at high RHML orders as compared to continuous-wave lasing mechanism.     

光纤光栅外腔半导体激光器的输出特性

采用射线法,计及增益随波长的变化,导出了光纤光栅外腔半导体激光器输出谱及输出功率的表达式。结合载流子速率方程,对外腔半导体激光器的输出谱的精细结构以及P-I特性进行了数值模拟研究。结果表明:光纤光栅外腔的输出谱在反射带宽内呈现出多峰结构,随着前端面反射率越小,输出谱相应地比较稳定;P-I特性曲线抖动越来越小,趋于线性变化。