1.3μmInGaAsP/InP涂层结构超辐射发光二极管输出特性的理论和实验

本文用考虑了增益饱和和热效应的耦合速率方程,对减反射涂层结构1.3μmInGaAsP/InP超辐射发光二极管的输出特性进行了计算,给出了腔长、有源层厚度和后腔面反射率对其输出光功率的影响以及光谱半宽随腔长和注入电流的变化。计算结果与我们制备的该结构超辐射发光二极管测试结果有较好的符合。     

1310 nm高功率超辐射发光二极管的制备及性能研究

为优化1310 nm超辐射发光二极管输出性能,提高器件输出功率,针对J型波导结构的1310 nm超辐射发光二极管的波导结构参数及器件散热能力进行研究.结果表明波导刻蚀深度、弯曲角度和绝缘层厚度是影响器件实现高功率输出的重要因素.基于研究结果对超辐射发光二极管器件结构及工艺进行优化,制备出脊宽5μm、弯曲角度8°、刻蚀深...     

超辐射发光二极管的输出特性

利用多模速率方程组的解析解对超辐射发光二极管的输出特性进行了研究。在此基础上数值模拟了衡量超辐射发光二极管工作的重要参量发输出线宽和输出功率等随端面反射率的变化，并且分析了它们之间的相互关系，实验结果与理论大致相符。     

决定AlGaInP高亮度发光二极管光提取效率的主要因素

影响发光二极管光提取效率的主要因素有:出光表面状态、上电极和体内吸收.对于AlGaInP高亮度发光二极管体内吸收主要是衬底和发光区的吸收.一般采用出光表面粗化、窗口层、DBR反射器等措施来提高光提取效率.本文以自发辐射随机分布模型为基础,以AlGaInP高亮度发光二极管典型结构的各种参数为依据,从理论上分析了这几种主要措施对光提取效率的影响.     

决定AlGaInP高亮度发光二极管光提取效率的主要因素

影响发光二极管光提取效率的主要因素有：出光表面状态、上电极和体内吸收．对于ＡｌＧａＩｎＰ高亮度发光二极管体内吸收主要是衬底和发光区的吸收．一般采用出光表面粗化、窗口层、ＤＢＲ反射器等措施来提高光提取效率．本文以自发辐射随机分布模型为基础，以ＡｌＧａＩｎＰ高亮度发光二极管典型结构的各种参数为依据，从理论上分析了这几种主要措施对光提取效率的影响．     

低偏振高功率1 310 nm超辐射发光二极管的液相外延生长

对新月形超辐射发光二极管的液相外延生长过程进行了机理分析。利用Matlab软件对建立的非平面生长模型进行了理论计算,并利用扫描电镜(SEM)对液相外延生长的形貌进行了分析,通过理论计算与实验分析设计了获得低偏振、高功率超辐射发光二极管的外延结构。利用该结构研制的超辐射发光二极管芯片在100 mA工作电流、25 ℃工作温度下输出功率达到3.6 mW,相应的输出波长为1 306 nm, 光谱半宽为39 nm,光谱波纹为0.17 dB,偏振度为2%。     

1 μm波段高功率超辐射发光二极管

为提高1μm波段超辐射发光二极管的输出特性,对外延结构及J型波导结构参数进行研究,基于研究结果确定外延结构及波导结构参数并对电极窗口制备工艺及单层氧化铪薄膜成膜条件进行了优化。研究表明,缩小波导与限制层AlGaAs材料中Al组分差值利于改善器件光束特性。此外,增加刻蚀深度、脊宽及曲率半径均会使损耗系数减小以提高器件输出功率。基于仿真结果制备出非均匀阱宽大阱深的三量子阱结构器件,前腔面镀制反射率约为0.5%的单层氧化铪薄膜,后腔面蒸镀高反膜,腔长约2 mm,波导曲率半径为21.8mm,在500 mA连续电流注入下,实现了118.1 mW输出功率和32.5 nm光谱半宽。单层增透膜的设计抑制了器件激射并简化了工艺复杂度,避免了多层增透膜不同材料间的应力问题。     

GaAlAs/GaAs非均匀阱宽多量子阱超辐射发光管材料制备及表征

超辐射发光二极管(SLD)具有不同于半导体激光器和普通发光二极管的优异性能。为了制备高功率半导体超辐射发光管,并且得到比较大的光谱宽度、大的单程增益和抑制电流饱和,我们研究设计了具有850nm辐射波长的GaAlAs/GaAs非均匀阱宽多量子阱超辐射发光二极管结构,采用分子束外延(MBE)方法进行了材料制备。同时利用X射线双晶衍射,变温(10～300K)光致发光(PL)等方法检测分析了外延薄膜的结构和光电特性。在光致发光谱线中我们得到了发射波长850nm的谱峰,谱峰范围跨跃800～880nm,双晶回摆曲线结果显示了设计的结构得到实现。在注入电流140mA时,器件输出光谱的半峰全宽可以达到26nm,室温下连续输出功率达到6mW。     

GaAIAs／GaAs非均匀阱宽多量子阱超辐射发光管材料制备及表征

超辐射发光二极管（SLD）具有不同于半导体激光器和普通发光二极管的优异性能。为了制备高功率半导体超辐射发光管，并且得到比较大的光谱宽度、大的单程增益和抑制电流饱和，我们研究设计了具有850nm辐射波长的GaAlAs／GaAs非均匀阱宽多量子阱超辐射发光二极管结构，采用分子束外延（MBE）方法进行了材料制备。同时利用X射线双晶衍射，变温（10～300K）光致发光（PL）等方法检测分析了外延薄膜的结构和光电特性。在光致发光谱线中我们得到了发射波长850nm的谱峰，谱峰范围跨跃800～880nm，双晶回摆曲线结果显示了设计的结构得到实现。在注入电流140mA时，器件输出光谱的半峰全宽可以达到26nm，室温下连续输出功率达到6mw。     

光纤陀螺信号处理中SLD驱动电路设计

光纤陀螺用光源要求输出功率高、相干性低、稳定性好，超辐射发光二极管（SLD）是能满足这些要求的理想光源，目前国内光纤陀螺用的光源基本上主要选择超辐射发光二极管（SLD），从工程实际应用出发，介绍了超辐射发光二极管（SLD）驱动电路设计，以此来提高光纤陀螺性能。     

Quantum-dot superluminescent diode: A proposal for an ultra-wide output spectrum

We propose a novel superluminescent diode (SLD) with a quantum dot (QD) active layer, which should give a wider output spectrum than a conventional quantum well SLD. The device makes use of inhomogeneous broadness of gain spectrum resulting from size inhomogeneity of self-assembled quantum dots grown by Stranski– Krastanow mode. Taking a design made out in the In_xGa_1-xAs/GaAs system for example, the spectrum characteristics of the device are simulated realistically, 100–200 nm full width of half maximum of output spectrum can be obtained. The dependence of the output spectrum on In composition, size distribution and injection current of the dots active region is also elaborated.     

多量子阱超辐射发光二极管(SLD)热分布计算

对由8个量子阱所组成的条形超辐射发光二极管(Super luminescent diode,SLD)进行了热分析,计算了不同器件结构下的热阻和温度分布。计算结果表明,热阻变化受芯片宽度和长度的影响较大,可以达到两个数量级;当注入功率达到1W时,有源区的温度将接近50K。该分析对有效地设计芯片的结构,减少温度升高对SLD稳定性的影响具有指导意义。     

Highly dynamic and versatile pulsed fiber amplifier seeded?by?a?superluminescence diode

We propose and investigate a high power superluminescence diode (SLD) as a pulsed seed source for a highly dynamic and versatile pulse fiber amplifier system. The SLD provides, contrary to conventional Fabry?CPérot laser diodes, a smooth and broad output spectrum which is independent of the input pulse parameters. The output pulses from the SLD are as short as 10?ns with up to 150?mW peak power. Moreover, the pulses can be directly shaped by modulating the injection current of the SLD. Pulse shaping in an amplifier configuration is demonstrated without the observation of stimulated Brillouin scattering (SBS) due to the provided spectral bandwidth of 10?nm FWHM. Further spectral shaping was realized with a band pass filter in the amplifier chain.     

大功率、宽光谱超辐射发光管的温度稳定性研究

超辐射发光管（SLD）的温度稳定性是通过芯片制作、耦合封装和应用控制三个环节实现控制. 在一定的驱动电流下,通过提高耦合效率、改善温控器件的几何参数以及器件整体的热分布参数,实现SLD大功率、宽光谱的光功率输出,出纤光功率达到750μW／100mA,光谱宽度大于40nm. 工作温度范围为－40～＋70℃,功率波动小于2 ％.     

1.55 μm InGaAsP/InP tapered stripe superluminescent diodes with potential optical sensor system applications

We proposed a structure of a 1.55 μm InGaAsP/InP superluminescent diode (SLD) to suppress the lasing action and fabricated laterally tilted multi-quantum well planar buried heterostructure separate confinement heterostructure SLD by using MOCVD and LPE equipments. The fabricated SLD is laterally tilted by 15°. The output power of SLD was 11 mW for 200 mA under pulse driving. The full-width at half-maximum was 42 nm at 200 mA.     

宽频脉冲光的传播特性

本文研究了宽频脉冲光在电磁诱导透明介质中的传播特性.结果表明,如果信号光的载波频率在透明窗口内,且频宽相对于透明窗口较宽时,输出信号光的时域宽度展宽,并出现明显的延迟效应;如果信号光的载波频率在介质吸收峰内,且频宽远大于介质吸收峰线宽时,信号光在传播过程中会发生形变,输出信号出现两个峰,峰值依赖于耦合光的频率和光强以及样品的长度,在适当条件下,在输出信号光中可获取较强的时域窄化的光脉冲. 关键词： 电磁诱导透明 脉冲形变 时间延迟 相干叠加     

光纤陀螺用光源全温度工作交越失真研究

为提高光纤陀螺准确度、实现工程化应用,分析了SLD光源内部的热结构,建立了全数字光源控制系统.测试结果表明：在变温环境下（－15℃～55℃）,抑制了光源的“交越失真”现象,实现了光源平均波长波动0.014％,光功率波动0.4％的控制准确度.采用抑制交越失真控制的光源的FOG在全温度范围内的零偏稳定性从2.14°/h提高到0.21°/h.     

Modeling the thermomechanical processes in the output window of a high-power СО<Subscript>2</Subscript> laser

A mathematical model of thermomechanical processes in the output window of a high-power continuous gas laser is developed and used to examine the windows of a СО₂ laser. The dependence of the maximum allowed output radiation power on the beam diameter and the distributions of temperatures and mechanical stresses are obtained, and the divergence of radiation is studied for windows made from ZnSe, KCl, and polycrystalline diamond (PD). In addition, the damage threshold of a composite output window made from PD with a single-crystalline region at the center is considered.     

Detection of nano scale thin films with polarized neutron reflectometry at the presence of smooth and rough interfaces

By knowing the phase and modules of the reflection coefficient in neutron reflectometry problems, a unique result for the scattering length density (SLD) of a thin film can be determined which will lead to the exact determination of type and thickness of the film. In the past decade, several methods have been worked out to resolve the phase problem such as dwell time method, reference layer method and variation of surroundings, among which the reference method and variation of surroundings by using a magnetic substrate and polarized neutrons is of the most applicability. All of these methods are based on the solution of Schrödinger equation for a discontinuous and step-like potential at each interface. As in a real sample there is some smearing and roughness at the boundaries, and consideration of smoothness and roughness of interfaces would affect the final output result. In this paper, we have investigated the effects of the smoothness of interfaces on the determination of the phase of reflection as well as the retrieval process of the SLD, by using a smooth varying function (Eckart potential). The effects of the roughness of interfaces on the same parameters have also been investigated by random variation of the interface around its mean position.