Ultralow Threshold Red Vertical-Cavity Surface-Emitting Lasers

Visible Vertical-cavity Surface-emitting Lasers (VCSELs) have been designed and fabricated by using metalorganic vapor phase epitaxy. Using the 8λ optical cavities with 3 quan tum wells in A1GaInP/AlGaAs VCSEL's to reduce the drift leakage current and enhance the model gain, the device can operate continuous wave at wavelength of 670nm. For better performance, a misoriented (100) substrate (6～10° to (110)) has been used to reduce the ordering of AlGaInP. However, as the angle of misorientation increased, the symmetry of the structure became worse. This made it difficult to achieve little aperture device. By using 45° rotated selective oxidation method, a little aperture (1 × 1μm2) device with low threshold of 0.25mA can operate continuous wave at room temperature.     

Red Light Vertical-Cavity Surface-Emitting Lasers

Vertical-cavity surface-emitting lasers (VCSELs) have entered into commercial market over the last few years. The paper describes the progress of visible (red) VCSELs in particular. The Basic experimental structures are reviewed, with emphasis on distributed Bragg reflectors, gain media, as well as detuning.lt also points out some technical issues that must still be resolved. Finally, the polarization of VCSELs devices is discussed.     

Temperature Analysis of Threshold Current in Infrared Vertical-Cavity Surface-Emitting Lasers

The temperature dependence of threshold current$I_ th$in vertical-cavity surface-emitting lasers (VCSELs) can be approximated by the equation$I_ th (T) = alpha + beta (T-T_min)^2$, where$T_min$is the temperature of lowest$I_ th, alpha$and$beta$are parameters, and temperature is$T$. We compare the temperature dependence of threshold current in VCSELs with GaAs, InGaAs, and strain compensated InGaAs–GaAsP quantum wells. From our analysis we find the coefficient$beta$is related to the gain properties of the quantum well, and is shown to serve as a benchmark for the VCSEL temperature sensitivity. The incorporation of strain-compensated high-barrier GaAsP layers in the active region of 980-nm VCSELs is demonstrated to reduce the threshold dependence on temperature.     

Zn扩散工艺在降低VCSELp型DBR串联电阻中的应用

垂直腔面发射激光器Ｐ型λ／４分布布喇格反射镜由于在ＡｌＡｓ／Ａｌ０．１Ｃａ０．９Ａｓ材料λ／４堆积层界面处存在大的势垒差，使得Ｐ型ＤＢＲ串联电阻很大。     

光子晶体垂直腔表面发射激光器及最佳化设计

单基模垂直腔表面发射激光器(VCSEL)在光网络数据传输、光互连、光存储和激光打印中有潜在的应用前景。光子晶体垂直腔表面发射激光器(PC-VCSEL)已成为备受关注的研究课题。介绍了PC-VCSEL的结构、最佳化设计及特性。     

氧化限制型垂直腔面发射激光器串联电阻分析

含氧化限制孔的VCSEL具有低的阈值电流，但氧化孔的存在也会加大串联电阻．本文采用理论模型，详细计算了氧化限制型VCSEL的串联电阻．把串联电阻分解为垂直方向电阻和横向电阻，分析了串联电阻与氧化孔半径的关系，提出了降低VCSEL串联电阻的具体方法．     

液晶可调谐VCSEL中高对比光栅结构的设计

基于严格耦合波理论设计了一种以液晶为低折射率材料的Si-SiO2复合高对比光栅,该光栅适合用于实现液晶可调谐功能的垂直腔面发射半导体激光器件。当940nm的TM偏振光入射时,通过优化参数可得到宽带(Δλ=256nm)高反射率(R>99%)且具有偏振稳定性的光栅结构,满足垂直腔面发射半导体激光器顶部腔面反射镜要求。液晶折射率的改变不会影响光栅的性能,未来有望将高对比光栅或混合光栅与液晶可调谐垂直腔面发射半导体激光器相结合,实现可调谐半导体激光器。     

用于垂直腔面发射激光器的GaAs/AlGaAs的ICP刻蚀工艺研究

采用电感耦合等离子体(ICP)刻蚀设备对应用于垂直腔面发射激光器的GaAs/AlGaAs材料进行刻蚀工艺研究。该刻蚀实验采用光刻胶作为刻蚀掩模,Cl2/BCl3作为刻蚀工艺气体,通过实验分析总结了ICP源功率、射频偏压功率和腔体压强对GaAs/AlGaAs材料和掩模刻蚀速率的影响。利用扫描电子显微镜观察不同参数条件对样品侧壁垂直度和底部平坦度的影响。最终在保证高刻蚀速率的前提下,通过调整优化各工艺参数,得到了侧壁光滑、底部平坦的圆台结构。     

高铝Al_xGa_(1-x)As氧化层对垂直腔面发射激光器的影响

针对可见光垂直腔面发射激光器的制备 ,通过湿氮氧化实验和测量微区光致发光谱分别研究了高铝组分Alx Ga1 - x As的氧化特性及氧化产物的收缩应力对有源区的影响 ,结合器件结构设计确定了氧化限制层 Alx Ga1 - x-As的铝组分和最佳位置 ,并制备出了低阈值电流的 Al Ga In P系垂直腔面发射激光器     

基于VCSEL的RCE探测器光电响应特性

对垂直腔面发射激光器（VCSEL）及由此制成的谐振增强型（RCE）光电探测器进行分析研究，激光器的Ith=3mA,ηd=15%,λp=839nm，和Δλ1／2=0．3nm，具有良好的波长选择特性，量子效率5％－35％（0V－5V），优化设计顶镜反射率，还能得到量子效率峰值和半宽优化兼容的VCSEL基RCE光电探测器。     

VCSEL技术及其在光互连中的应用

垂直腔表面发射激光器（VCSELs）是并行光互连、高速光交换系统中最合适的光源。它具有易耦合、易封装和测试的优点。由于其独特的性能，可以较为方便地制作二维激光器阵列。基于VCSEL阵列的光电混合集成及并行光互连是当前的研究热点。本文介绍了VCSEL基本结构及设计中的关键技术，并对VCSEL在光互连中的应用进行了研究。     

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。     

Analytical Expression of the Threshold Pump Power of Erbium－doped Fiber Lasers Pumped at 980nm and 1480nm Wavelengths

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Analytical Expression of the Threshold Pump Power of Erbium—doped Fiber Laeers Pumped at 980 nm and 1480nm Wavelengths

The rate equations,which is suiable to erbium-doped fiber lasers pumped at 980 nm and 1480 nm wavelengths respectively,are investigated,and analytical ex-pressions of the threshold pump powers under two pump wavelengths are derived.As a result,some important parmeters can be quantitatively specified.     

降低VCSELs激射阈值途径的理论研究

针对量子阱有源层的结构特点，考虑增益和载流子浓度呈对数关系，建立量子陆垂直腔面发射半导体激光器（VCSEL）的速率方程，导出了阈值电流密度的解析表达式，运用MATLAB软件中Simulink可视化仿真系统对理论计算进行模拟仿真，研究了降低VCSEL激射阈值的3个基本途径；有源层选用量子阱实现微腔结构，腔面采取多层介质反射膜提高光腔反射率R：改进外延生长技术在降低各种损耗。