多量子阱垂直腔面发射半导体激光器的速率方程分析

依据多量子阱垂直腔面发射半导体激光器（ＶＣＳＥＬＳ）的结构特点,并考虑到腔量子电动力学中自发辐射增强效应,建立了多量子阱ＶＣＳＥＬＳ的速率方程,并给出了其方程的严格解析解,在此基础之上,讨论了ＶＣＳＥＬＳ的稳态特性,并与普通开腔和三维封闭腔中的结果进行了比较,给出了Ｖ     

Input and intrinsic device modeling of VCSELs

An efficient model scheme that combines the non-linear behavior of the input parasitics with the intrinsic fundamental device rate equations of the Vertical Cavity Surface Emitting Lasers (VCSELs) is proposed. A systematic methodology for the model parameter extraction from dc and ac, electrical and optical measurements, is also presented and simulation results are compared with the experimental measurements. Extraction and simulation procedures are implemented in commercial integrated circuit design tools and they are proved to be very fast while they preserve adequate accuracy.     

外光反馈下VCSELs噪声灵敏性的理论研究

从速率方程出发，仿真得到VCSELs在不同腔体结构、自发辐射因子和线宽限制因子情况下，相对强度噪声随外光反馈水平的变化规律。结果表明：减小电流孔径或线宽增强因子可以降低VCSELs对外光反馈的灵敏性，改变自发辐射因子对此影响不大。而传统边发射激光器不属于微腔结构，对外光反馈的抑制能力较弱。     

垂直腔面发射激光器新型结构的特性比较

通过对一种微分量子效率可以大于1的新型多有源区隧道再生应变量子阱垂直腔面发射半导体激光器(VCSELs)结构,以及由此设计出的阈值电流更小、输出功率更大的器件与普通结构在反射率及注入电流都相同的条件下输出功率大小的比较及阈值电流密度大小的比较,从而在理论上证实了这种VCSELs新型结构的优势。     

VCSELs与EELs多模弛豫振荡的研究

根据多模速率方程,利用MATLAB提供的SIMULINK软件包对垂直腔面发射激光器(VCSELs)和边发射激光器(EELs)多模弛豫振荡进行了研究。结果表明,与单模情况相比,多模时EELs弛豫振荡频率增大、弛豫和延迟时间缩短,而VCSELs动态特性变化不大。与此同时,在得出VCSELs的单模工作、高速调制以及提高偏置电流或自发辐射因子可改善两类器件动态特性等结论外还看到,VCSELs边模抑制比(SMSR)随偏置电流变化率高于EELs;自发辐射因子增大时,边模强度同比例增大、主模强度减小,利用微腔效应有效控制自发辐射因子可以优化VCSELs的单模特性。     

Analysis Expression of Rate Equation for Vertical Cavity Lasers

An analysis solution of rate equation is derived for vertical cavity surface-emitting lasers.Based on the enhanced spontaneous emission caused by VCSELs and influence of nonradiative recombination, the relation between output properties and structural parametersof multi-quantum wells(MQWs) is obtanined.It was found that the characteristic curve of a “thresholdless“ laser is strongly nonradiative depopulation-dependent.When the nonradiative depopulation is no zero,the light-current characteristic is not linearly even for an ideal closed microcavity.The light output is increased by the enhanced well number and by the reduced width.In particular, a lower threshold current density for MQWs structure in the short cavity is realized by us, meanwhile the sharpness of the variation depends on spontaneous emission factor.     

Electrical characterisation of p-doped distributed Bragg reflectors in electrically pumped GaInNAs VCSOAs for 1.3 μm operation

The high resistivity that is encountered in p-type DBRs is an important problem in vertical cavity surface emitting lasers and optical amplifiers (VCSELs and VCSOAs). This is because the formation of potential barriers at the interfaces between layers of high and low refractive index inhibits the carrier flow, thus increasing the DBR series resistance. In this work, the electrical characteristics of two p-type doped DBR structures grown on undoped and p-type doped GaAs substrates have been investigated. The DBRs are designed for VCSOAs operating at 1.3 μm and consist of 14-periods of alternating GaAs and Al_0.9Ga_0.1As in the first sample and 14-periods of GaAs and Al_0.3Ga_0.7As/Al_0.9Ga_0.1As in the second one. For the longitudinal transport sample, Hall mobility and sheet carrier density were measured in the temperature range from 77 to 300 K. In the vertical transport sample, current–voltage (I–V) measurements across the DBR layers were carried out at different temperatures in the range between 15 and 300 K. We achieved resistivity reduction in our samples by using an interface composition grading technique aimed at improving the VCSOA characteristics.     

垂直腔面发射激光器光场数值解的打靶法

利用传输矩阵法得到了垂直腔面发射激光器（VCSELs）内部光场应满足的本征方程，并通过打靶法对方程进行了求解。数值结果表明，该方法具有求解速度快和精度高的优点。用该方法模拟分析了有源区两侧GaAs垒层的厚度及spacer层中的Al组份对阈值增益、光限制因子和共振波长的影响。     

Few-mode vertical-cavity surface-emitting lasers for space-division multiplexing

In order to choose the proper radius of oxide aperture for few-mode vertical-cavity surface-emitting lasers (VCSELs), the influences of oxide aperture size on the multi-transverse-mode behaviors are investigated in detail. By establishing the effective refractive index model to simulate VCSELs with different radii of oxide apertures, the wavelength and corresponding order of different modes are obtained. VCSELs with three kinds of oxide apertures are manufactured. Then the multi-transverse-mode spectra and near-field are measured. It is found that when the radius is between 1.5 and 4.5 μm, few-mode VCSELs can be implemented. The 2.5 μm VCSEL manufactured in this paper only emits LP01 mode and LP21 mode. Since the space distance between the two modes is 2 μm, it is expected to realize direct-modulation few-mode VCSELs by channel etching or ion implantation between the two modes.     

大功率短脉冲VCSELs的特性研究

研究了大功率短脉冲垂直腔表面发射激光器(VCSELs)出光孔径分别为400μm,600μm的980nm倒封装底发射VCSELs的脉冲特性,通过测试脉冲电流源产生的电脉冲的波形曲线以及产生的光脉冲的脉冲响应曲线,得到脉冲峰值功率与输入电流的P-I曲线,600μm直径的VCSELs在脉冲宽度为60ns,重复频率为1kHz时,得到超过20W的峰值输出功率;激射波长为976.6nm,器件的光谱半高宽(FWHM)为0.9nm.