新型多量子阱锁模半导体激光器的实验研究

报道了一种主要用作超高速光纤通信系统的新型半导体光源,即超高速10 GHz、多量子阱、主被动混合锁模的半导体激光器,其输出光波长可精确稳定在1550 nm,这对实现光时分复用技术高质量超短相干脉冲光源具有重要意义。     

新型多量子阱锁模半导体激光器的实验研究

报道了一种主要用作超高速光纤通信系统的新型半导体光源，即超高速10GHz、多量子阱、主被动混合锁模的半导体激光器，其输出光波长可精确稳定在1550nm，这对实现光时分复用技术高质量超短相干脉冲光源具有重要意义。     

新型多量子阱被动锁模半导体激光器噪声分析

对多量子阱被动锁模半导体激光器的噪声理论进行了系统的分析 ,并给出了半导体激光器腔内相位随载流子浓度变化的关系。研究表明 ,被动锁模半导体激光器 (MLLDs)的总噪声主要由散粒噪声、自发辐射放大噪声、频率调制噪声和量子噪声组成 ,分别由光场的振幅、频率和载流子的相位噪声等所致的结果     

半导体多量子阱激光器的波导模式分析

本文以多层结构波导模式的精确解为准,讨论了各种等效折射率法,并对量子尺寸效应的影响提出一个考虑到阱间相互作用强弱的半经验的处理方法,得出与最近多量子阱实验数据符合较好的结果.     

碰撞锁模多量子阱半导体激光器模式锁定过程的物理模型

提出了碰撞锁模多量子阱激光器模式锁定过程的完整的物理模型，该模型全面地考虑了吸收体的饱和吸收效应和瞬态光栅效应及增益区端面附近和靠近吸收体处的瞬态光栅作用。作为应用实例采用本模型研究了多量子阱结构激光器的模式锁定过程及瞬态光栅对脉冲半峰宽及峰值功率的影响。     

量子阱半导体激光器概述

本文主要从量子理论中的电子波函数所满足的薛定锷方程出发,讨论了量子阱理论。进而介绍多量手阱激光器(MQWL)的重要特征之一——阈值电流密度随量子阱的数目变化的情况。     

大功率半导体量子阱激光器及其应用

本文综述了量子阱应变层异质结构的大功率半导体激光器的优化特性，阐述了大功率激光器的一些重要应用，比如用８０８ｎｍ波长的大功率激光器可作为泵浦光源代替庞大的氙灯泵浦系统，还可以用作激光核反应的前级大功率激光漂；大功率半导体激光器发射的波长可以精确地控制在９８０ｎｍ，并能高效率地耗合到光纤中去，有很高的泵浦效率，从而半导体激光泵浦的光纤放大器为光通信技术的发展作了突破性贡献，大功率半导体激光器还在军工     

量子阱半导体激光器发展动态

综述了近几年来国外在量子阱半导体激光器方面的开发现状，着重阐述了在提高器件性能方面获得低阈值电流，降低α参数和线宽的重要性。     

1.3 μm multiquantum well decoupled confinement heterostructure(MQW-DCH) laser diodes

A 1.3-μm multi-quantum-well decoupled confinement heterostructure (MQW-DCH) laser diode has been developed. This structure introduces internal barriers between the active quantum wells and the optical waveguide. It is thus possible to have, at the same time, deep quantum wells to prevent carrier leakage and a strong optical waveguide with a high confinement factor. The barrier parameters have been optimized using numerical modeling tools, and the DCH laser diode has been built using chemical beam epitaxy. The broad-area transparency current density is 140 A-cm^-2, the internal efficiency is 0.83, the waveguide loss is 5 cm^-1. and T₀ = 62 K. Ridge waveguide laser diodes have a room temperature threshold of 8 mA and an efficiency of 0.32 mW/mA     

Evaluation of multiquantum barriers in bulk double heterostructure visible laser diodes

Three bulk (Al/sub x/Ga/sub 1-x/)/sub 0.5/In/sub 0.5/P double heterostructure (DH) lasers were designed and fabricated to examine the effect of incorporating multiquantum barrier (MQB) structures. The first laser, used as a reference, has a conventional structure, while the remaining lasers include MQB structures, one designed to achieve a virtual barrier of 75 meV, the other having a transmission window up to 100 meV above the bulk barrier height. Measurements show a reduction of up to 31% in the room temperature threshold current and an increase in characteristic temperature of 20 K by the inclusion of the optimized MQB structure in comparison with the reference laser. However, since the leaky MQB design also shows a significant room temperature improvement over the reference laser we suggest that the device improvements produced by the MQB structures are not solely due to the formation of a virtual barrier.     

高功率1.31μmAlGaInAs应变多量子阱DFB激光器

采用金属有机化学汽相淀积工艺和脊型波导结构,同１．３１μｍＡｌＧａＩｎＡｓ／ＩｎＰ应变多量子阱分布反馈激光器高功率输出。在２５℃时,管芯最大输出功率超过５０ｍＷ,阈值电流范围在１３－２０ｍＡ之间,发光面斜效率高于０．４５ｍＷ／ｍＡ,边模抑制比超过３５ｄＢ,室温中值寿命大于３＊１０＾５小时。     

Demonstration of passive Q-switching in multiquantum well InGaAs/AlGaInAs diode laser

The first passive Q-switched operation is reported of an InGaAs-AlGaInAs diode laser with a frequency repetition ranging from 1 to 2.5 GHz at the emitting wavelength of 1.58 /spl mu/m. This material is important as a thermally stable alternative to InGaAsP based laser systems operating around 1.5 /spl mu/m.     

Optical and electrical characterization of (Ga,Mn)N/InGaN multiquantum well light-emitting diodes

(Ga,Mn)/N/InGaN multiquantum well (MQW) diodes were grown by molecular beam epitaxy (MBE). The current-voltage characteristics of the diodes show the presence of a parasitic junction between the (Ga,Mn)N and the n-GaN in the top contact layer due to the low conductivity of the former layer. Both the (Ga,Mn)N/InGaN diodes and control samples without Mn doping show no or very low (up to 10% at the lowest temperatures) optical (spin) polarization at zero field or 5 T, respectively. The observed polarization is shown to correspond to the intrinsic optical polarization of the InGaN MQW, due to population distribution between spin sublevels at low temperature, as separately studied by resonant optical excitation with a photon energy lower than the bandgap of both the GaN and (Ga,Mn)N. This indicates efficient losses in the studied structures of any spin polarization generated by optical spin orientation or electrical spin injection. The observed vanishing spin injection efficiency of the spin light-emitting diode (LED) is tentatively attributed to spin losses during the energy relaxation process to the ground state of the excitons giving rise to the light emission.     

Carrier-induced lasing wavelength shift for quantum well laser diodes

Lasing wavelength was analyzed for quantum well laser diodes (QW-LD's) considering both the bandgap shrinkage effect and the band-filling effect. The bandgap shrinkage effect was calculated by the local density functional method, treating both electron and hole distribution self-consistently. Assuming nok-selection rule, the band-filling effect is larger than the bandgap shrinkage effect when the carrier density is high. The lasing wavelength shifts to the short side as the threshold carrier density increases. QW-LD's with a large threshold carrier density lase at very short wavelength corresponding to the transition between the second sublevel. However, this wavelength is still longer than that expected because of the bandgap shrinkage effect.     

8×2.5Gbit/s光时分复用信号产生系统

介绍由２×２光纤耦合器进行级联实现的８×２．５Ｇｂｉｔ／ｓ光时分复用信号产生系统，信号源采用增益开关量子阱ＤＦＢ激光器，脉冲周期为４００ｐｓ。实验结果表明，采用这种方案实现的时分复用信号产生系统，插入脉冲的间隔均匀，脉冲的波动小且损耗低。     

超高速激光熔覆头非稳态追踪粉末流场研究

超高速激光熔覆技术取代电镀铬,可解决电镀铬工艺重金属铬离子(Cr6+)重金属污染,被禁止或限制的工业应用问题.金属工件表面镀硬铬,集耐蚀性防护、装饰于一体,有着巨大的应用前景.我国超高速激光熔覆技术的研发,主要侧重点在于设备集成与工艺实验研究,缺少熔覆过程仿真模型.本文以超高速激光熔覆环形熔覆头为研究对象,利用FLUE...     

AlGaAs/GaAs lateral current injection multiquantum well (LCI-MQW)laser using impurity-induced disordering

A lateral current injection (LCI) multiquantum-well (MQW) laser having planar structure is proposed and its advantages compared with conventional vertical structure lasers. A LCI-MQW laser has been fabricated by using Si- and Zn-induced disordering of an MQW active layer. It is shown that a threshold current of 27 mA is achieved under pulsed current driven at room temperature and a very low stray capacitance of 0.27 pF is obtained at zero bias voltage     

全光时分复用系统光时分复用信号产生研究

利用５０：５０耦合器以２×２级联的形式研制成功２×２．５Ｇｂ／ｓ、４×２．５Ｇｂ／ｓ和８×２．５Ｇｂ／ｓ光时分复用信号产生系统。用增益开关量子阱ＤＦＢ激光器产生的宽度为１９ｐｓ、周期为４００ｐｓ的光脉冲作为源信号脉冲所进行的实验表明，在精确控制光程差的基础上用级联形式制作的时分复用信号产生系统产生的信号完全可以满足基础应用研究要求。