日本开发出半导体泵浦白色光纤激光源

日本住田光学玻璃公司开发了一种半导体泵浦白色光纤激光源。该光源采用440nm蓝色半导体激光器泵浦掺镨氟化铝玻璃光纤，产生522nm和635nm激光输出，与蓝色泵浦光一起合成白色光源。由于使用了半导体激光器，所以与原来利用YAG激光器等固体激光器以及He-Cd激光器等气体激光器产生的三基色光源的办法相比，具有转换效率高、耗电少、设备体积小及成本低等优点。     

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     

电子束扫描激发的半导体激光器

１９６１年巴索夫等提出并论证了用电子束泵浦在半导体中建立粒子数反转的方法［３］，其后在实验上首次研制成电子束泵浦的半导体激光器［６，９８］。作者认为，到目前为止俄国在该领域仍占领光地位。由于前不久发表过该类激光器的综合评述［９８，１００］，本文仅涉及...     

LD热弛豫时间与泵浦光谱效率的改进

采用测试半导体激光器热弛豫时间的新方法,测量光信号脉冲内不同时刻的时间分辨光谱,测试了TO封装和cm-Bar列阵的AlGaAs/GaAs半导体激光器泵浦光源,得到其热弛豫时间分别为为66 μs和96μs.在目前常用的方波驱动电流脉冲工作条件下,半导体激光器作为固体激光器泵浦源,如果热弛豫时间过长,单个脉冲内激射波长会偏离固体激光介质的吸收带,导致泵浦光波长利用率和有效泵浦能量降低.为克服现有技术的不足,文中提出了两种新型的驱动电流脉冲波形,通过优化电流波形参数可以将泵浦波长利用率提高30%左右,得到更大的有效泵浦能量.     

大功率半导体激光器模块散热结构的数值优化

考虑大功率半导体激光bar外延结构中GaAs衬底热阻导致p、n面散热的非对称性,利用商用有限元软件Ansys对目前常用的DPSSL侧泵浦源亚封装子模块的散热性能进行了分析和结构优化,并根据优化结构实际制备出3 bar激光线阵泵浦源,其连续输出功率超过120 W,中心波长为807.7 nm,光谱宽度(FWHM)为2.8 nm.该数值分析结果对根据实际需要设计、封装出不同结构尺寸的大功率半导体激光泵浦源模块具有现实的指导意义.     

利用盘形激光器进行微细加工

目前高输出功率YAG激光器的主流是半导体泵浦的棒状YAG激光器，而在新的应用领域中，高质量的LD泵浦的盘形YAG激光器则倍受人们的关注。本文主要介绍LD泵浦的盘形YAG激光器的研发现状及其应用。     

1．45μm及1．47μm半导体激光器泵浦的掺铒光纤放大器实验研究

利用１．４７μｍ及１．４５μｍ半导体激光器泵浦的掺铒光纤放大器进行了实验研究。结果表明，用１．４５μｍ半导体激光器泵浦掺铒光纤也能对信号光放大。用１．４５μｍ和１．４７μｍ半导体激光器双向泵浦掺铒光纤，获得了２７ｄＢ的增益。     

半导体泵浦固体激光器在激光加工中的应用

介绍了激光加工的优点和对激光器输出参数的要求，对固体激光器中发展最活跃的半导体泵浦全固体激光器进行了分析。在对当前的几种主要结构比较后，指出盘形激光器和光纤激光器将在未来的激光加工中发挥更大的作用。     

北京国科世纪激光技术有限公司

北京国科世纪激光技术有限公司是中科院控股的高新技术企业，成立于2002：年4月，总部位于北京市海淀区上地信息产业基地。国科世纪激光技术有限公司是先进固体激光器及其应用系统的专业生产商，拥有及可供使用的发明和实用新型专利30余项．并多次承担北京市科委、国家863计划等多个重大项目。主要产品现有半导体激光泵浦源、半导体泵浦激光器、复杂激光器、半导体泵浦激光系统、光纤耦合模块系统和半导体激光电源及Q驱动源6大系列，并于2004年10月通过ISO9001质量管理体系认证。另外，公司可承接陶瓷刻划、硅片、太阳能薄膜电池薄膜、特殊精细标识用激光应用设备．     

半导体侧面泵浦固体激光器均匀性的计算和分析

建立了半导体侧面泵浦固体激光介质内泵浦光能吸收分布情况的数值模型。模拟计算了不同泵浦参数下棒状介质和板条介质内泵浦光能的吸收分布,计算结果和有关实验结果符合得很好。得出了半导体侧面泵浦机构中介质尺寸、介质吸收系数和半导体激光器发光面到介质泵浦面距离这三个参数对泵浦均匀性的影响,比较了棒状介质和板条介质在半导体侧面泵浦应用中的优劣。     

氟化物玻璃在两束激光作用下的上转化三维立体显示

研究了两束激光作用下的上转换三维(3D)立体显示,所用材料为ZBLAN:Pr,Yb氟化物玻璃。所用的两束激光是波长分别为960 nm(半导体激光器)和820 nm(Ti宝石激光器)。对Pr3+离子双频上转换发光进行了研究,分析了上转换发光强度与抽运光强度和离子掺杂浓度的关系,从而得出了实现较清晰双频上转换3D立体图像的实验条件。ZBLAN玻璃为双频上转换3D立体显示的基质材料,主要由于其有非常好的声子光谱声子频率小于580 cm-1;当激光强度很小时,上转换荧光强度将随着两抽运激光强度的增加而线性增加;ZBLAN玻璃中Pr3+离子和Yb3+离子的最佳掺杂摩尔分数为0.5%和1.5%。     

Pumping with diodes

The development of semiconductor lasers for pumping solid-state laser crystals is discussed. The basic operating principles of solid-state devices are reviewed to show why this new development is so important. Among the first of the new diode-laser technologies to be applied to pumping was the phase-locked array, which produced much higher power outputs and higher brightness from room-temperature CW diode-laser systems. With diode-laser arrays capable of power outputs between 0.2 and 2 W, and relatively good beam quality, it became possible to pump Nd:YAG and other crystals longitudinally, with the pump and laser output beams either parallel or antiparallel in the laser crystal. Diode pumping allows the flowing cooling liquids and fluctuating arc lamps used in conventional lamp-pumped lasers to be replaced by solid heat sinks and stabilized pump lasers. As a result, designers can build low-power solid-state lasers having high mechanical and thermal stability. Short-term linewidths in the kilohertz range can be obtained from diode-pumped devices, and the long-term drift of monolithic devices can be kept within 50 MHz for over an hour (for a center frequency of 3×10⁸ MHz) by controlling the laser-crystal temperature     

Wavelength tuning of the stimulated emission from GaAs and CdSe electron-beam-pumped lasers

The wavelength at which the stimulated output from a number of electron-beam-pumped semiconductor lasers peaks is a function of the time after the start of the pumping pulse. In general, the output intensity reaches a maximum at short wavelengths considerably before it peaks at the longest. Detailed observations of the wavelength shifts of the peak output as a function of both time and pumping current are reported here for both CdSe and GaAs laser crystals. It is found that the rate of shifting of the wavelength peak (tuning rate) as a function of electron-beam pumping current is very similar in both functional form and magnitude in the two materials. Furthermore, the behavior of the tuning rate is dependent on whether or not lasing action occurs in the crystal under examination. For a crystal in which lasing action is obtained, the tuning rate saturates for pumping current densities above threshold. In contrast, for a nonlasing crystal, the tuning rate is a linearly increasing function of the pumping current density. The implications of these results are discussed with reference to previously reported work concerning shifts with respect to the band edge of the stimulated emission from semiconductor lasers.     

Multicomponent solid-solution semiconductor lasers

Properties of a new hetetrostructure based on quaternary alloys are presented in application to semiconductor lasers. Room temperature laser operation is obtained near 1.06 and 1.8 μm with injection pumping and near 2 μm with electron-beam pumping.     

Contribution of Auger recombination to saturation of the light-current characteristics in high-power laser diodes (λ = 1.0–1.9 m m)

Spectral and light-current characteristics of lasers based on the asymmetric separate-confinement heterostructures InGaAs/InGaAsAl/InP and InGaAs/GaAs/AlGaAs/GaAs were studied in the pulsed mode of lasing. It is shown that, at high levels of current pumping, the charge-carrier concentration in the active region of semiconductor lasers for the near-infrared optical region increases beyond the oscillation threshold; drastic saturation of the light-current characteristics is observed. Processes occurring in lasers as the charge-carrier concentration increases beyond the lasing threshold are studied theoretically. It is established that, at high pump levels, the rate of stimulated recombination decreases, the lifetime of charge carriers increases, and both the concentration of emitted photons and the quantum yield of stimulated radiation decrease. It is shown that variations in stimulated recombination, the decrease in the quantum efficiency, and saturation of the light-current characteristic in semiconductor lasers at high levels of current pumping are caused by the contribution of the nonradiative Auger recombination.     

Applications of Semiconductor Lasers

1 Introduction The world first diode laser was developed in 1962, only two years later than the demonstration of the first world ruby laser. The diode laser had moved from the pure re- search laboratory to the consumer market not until the 1980s, mainly driven by the demand from optical infor- mation storage and optical communication. Most diode lasers are made of semiconductor materi- als from groups III (Ga, As, In) and V (N, P, As) of the Periodic Table[1]. They are also diode lasers b…     

Mode-switching in semiconductor lasers

In this paper, we experimentally analyze the modal dynamics of quantum-well semiconductor lasers. Modal switching is the dominant feature for semiconductor lasers that exhibit two or several active longitudinal modes in their time-averaged optical spectrum. In quantum-well lasers, these dynamics involve a periodic switching among several longitudinal modes, which follows a well-determined sequence from the bluest to the reddest mode in the optical spectrum. This feature is radically different from the well-known noise-driven mode-hopping occurring in bulk lasers which involves only two main modes. We analyze the differences in modal dynamics for these two kinds of laser by comparing the modal switching statistics and by studying the effects of noise and modulation in the pumping current.     

New materials for diode laser pumping of solid-state lasers

The authors review recent progress in the development of new materials for III-V semiconductor diode lasers useful for pumping solid-state lasers. All of the diode lasers discussed are grown on GaAs substrates. Particular emphasis is placed on the performance and reliability of high-CW-power strained-layer InGaAs-AlGaAs diode lasers emitting in the wavelength range between 0.87 and 1.1 μm, improved resistance to degradation of 0.78 to 0.87 μm diode lasers afforded by the strained-layer AlInGaAs-AlGaAs and lattice-matched GaInAsP-GaInP materials systems, and improved performance of visible diode lasers utilizing the materials system GaInP-AlGaInP     

半导体激光器

Surface-emitting semiconductor lasers can make use of external cavities and optical pumping techniques to achieve a combination of high continuous-wave output power and near-diffraction-limited beam quality that is not matched by any other type of semiconductor source. The ready access to the laser mode that the external cavity provides has been exploited for applications such as intra-cavity frequency doubling and passive mode-locking.     

有机半导体电注入激光器

有机半导体激光器实现了从光泵浦到电泵浦。回顾了有机半导体激光器从光泵浦到电流入的发展过程。概述了有机半导体材料产生激光的特性,介绍了贝尔实验室第一个有机固态电注入型激光器的工作原理,提出了在器件结构上的一些新设想。