短激光脉冲产生的历史回顾

从１９９０年起人们就看到用固态激光器产生短和超短光脉冲方面的巨大进展。虽然即便首台被动锁模激光器是固态激光器（１）,但在１９８０年底以前,超短脉冲的产生主要用染料激光器（见图）。被动锁模染料激光器产生的脉冲短至２７ｆｓ,典型的平均输出功率约为１０ｍＷ...     

激光控制光电子开关产生的电脉冲激励半导体激光器产生超短光脉冲

最近,Kobayaashi等报导了用短电脉冲激励半导体激光器获得了超短光脉冲输出.而用锁模超短脉冲激光器驱动的半导体光电子开关能产生超短同步电脉冲.这里介绍的是用激光驱动的超快速开关产生的短电脉冲激励半导体激光器,得到同步的变频超短光脉冲的结果.     

孤粒子激光器

孤粒子激光器为超短光脉冲的产生提供了一个崭新的原理。在孤粒子激光器中，使用光纤(这种光纤是激光器反馈环路的组成部分)中的脉冲压缩和孤粒子，迫使激光器本身产生一定形状和宽度的脉冲。这个新原理能产生前所未有的超短脉冲。实际上，孤粒子激光器是近红外区域中第一种脉冲源。     

超短脉冲光纤激光器的研究进展

本文针对超短脉冲光纤激光器三种不同的锁模机制，综述了相应锁模光纤激光器的研究进展，并且对包层泵浦锁模光纤激光器产生高能量或高峰值功率超短脉冲进行了阐述。     

Nd~(3+)掺杂无序晶体被动锁模激光器的研究现状

全固态激光器被动锁模是产生超短脉冲的一种有效方法。在基于Nd~(3+)掺杂激光材料被动锁模产生超短脉冲的研究中,无序晶体成为研究的热点。结合相关工作,总结了Nd~(3+)掺杂无序晶体被动锁模激光器的研究现状,展望了Nd~(3+)掺杂无序晶体在超强超短脉冲制备中的发展前景。     

超短光脉冲的产生及其应用

本文评述超短光脉冲的产生技术及其应用的技术现状Q已使用各种产生脉冲的技术获得亚亳微秒脉冲。锁模是获得微微秒脉冲的一种特别重要的技术，本文着重详细评述最近发展起来的用于染料激光器和固体激光器的锁模方案。对用一台半导体激光器产生光脉冲的方法也作了概括，这种技术具有独特的特性。文中着重强调主动的光控制技术在产生超短光脉冲中的作用。从光电子学的观点上对不同的应用例子进行评述。     

利用0.85μm半导体激光器直接调制产生超短光脉冲

在模数转换、信号分路传输和光电取样系统中,要求采用的半导体激光器产生高重复率的超短光脉冲。我们用射频电流直接调制0.85μm的GaAs/GaAlAs半导体激光器,获得了重复频率为2GHz、脉冲宽度小于80ps的超短光脉冲。     

超短脉冲偏振分割放大技术研究进展(特邀)

介绍了超短脉冲偏振分割器的基本类型和放大器的光路布局,总结了国内外采用偏振分割放大技术抑制光纤非线性效应、提高超短脉冲输出能量和突破增益介质抗损伤阈值方面的新进展。重点报道了偏振分割放大技术在高重复频率高功率掺铒飞秒激光器研制方面的最新进展,基于双程放大结构和多级偏振分割,同时实现超短脉冲的非线性放大与脉冲压缩,结合光学倍频,获得百毫瓦百飞秒,中心波长780 nm的激光脉冲,为实现结构紧凑、使用方便、环境稳定、光束质量好的飞秒激光光源提供了一个有效的技术途径,有望部分替代钛宝石激光器,在太赫兹产生、生物医学成像、光学非线性效应研究等方面拓展应用。     

超短脉冲激光器及其应用

1引言 从激光发明的初期开始,超短脉冲光的产生和应用就有效地利用了激光的特点,科学家们对此开展了多项研究.近年来,作为物理科学研究和测量的工具,超短脉冲激光器在很多领域得到应用,并有望应用于三维加工或医疗方面.     

25飞秒CPM染料激光器的频率可调谐特性

本文报导可产生几十飞秒脉宽的可调谐超短脉冲染料激光器。该激光器腔内插有四个棱镜,适当放置四个棱镜的位置和取向,可使其具有两方面的功能:一则可以补偿锁模脉冲的啁啾,使锁模脉冲得到最大限度地压缩以产生几十飞秒的超短光脉     

High-power (>0.5-W CW) diode-pumped vertical-external-cavity surface-emitting semiconductor lasers with circular TEM/sub 00/ beams

We report demonstration of a new high-power semiconductor laser technology, the optically pumped semiconductor (OPS) vertical-external-cavity surface-emitting laser (VECSEL). Using diode laser pump, an OPS-VECSEL laser with a strain-compensated InGaAs-GaAsP-GaAs multiquantum-well (MQW) structure operated continuous-wave (CW) near /spl lambda//spl sim/1004 nm with record output power of 0.69 W in a TEM/sub 11/ mode, 0.52 W in a TEM/sub 00/ mode, and 0.37 W coupled to a single-mode fiber. It is feasible to produce greater than 1 W of power in a diffraction-limited circular beam from an efficient, compact, manufacturable and reliable OPS-VECSEL laser.     

输出参数可调的微宝石激光器设计

从激光二极管泵浦Cr4 :YAG被动调Q微宝石激光器速率方程出发,分析了微宝石激光器输出参数(脉冲能量、峰值功率、脉宽、重复频率)的影响因素,计算表明在激光模块(包括激光晶体、调Q晶体、镀膜)已定的情况下,输出激光脉冲的脉宽也已定,而改变泵浦面积可以同时改变脉冲能量、峰值功率、重复频率,改变泵浦速率只改变脉冲重复频率.在此基础上对输出参数可调的微宝石激光器进行了概念设计.     

半导体可饱和吸收镜实现超短高功率脉冲激光研究进展

介绍了半导体可饱和吸收镜(SESAM)的基本结构及使用半导体可饱和吸收镜被动锁模固态激光器的基本原理.综述了利用半导体可饱和吸收镜被动锁模薄片式固态激光器及光泵浦垂直外腔面发射半导体激光器,获得高平均输出功率超短脉冲的最新进展,并指出量子点半导体可饱和吸收镜的使用将加速超短高功率脉冲的发展.     

Fourier-transform-limited laser pulses tunable in wavelength and induration (400-2000 ps)

A combined system of an injection-seeded pulsed dye amplifier and a pulse compressor based on stimulated Brillouin scattering (SBS) is investigated. It allows for the generation of powerful pulses both tunable in wavelength and in duration. Online tuning of the pulse duration is possible due to the dependence of SBS compression on input energy. A range of 400-2000 ps at up to 100 mJ output energy is demonstrated. The output pulses are temporally and spectrally resolved to investigate the properties of this system. Coherent nearly Fourier-transform-limited pulses of variable pulse duration in the extreme ultraviolet (UV) are produced employing harmonic conversion. As an application of such pulses a single rotational line of H₂ at 98-nm wavelength is excited, demonstrating that the system may be used for laser-spectroscopic studies to simultaneously gain spectral as well as dynamical information     

双散热片结构光抽运垂直外腔面发射激光器的热特性分析

利用ANSYS有限元热分析软件对光抽运垂直外腔面发射激光器(OPS-VECSEL)内部的热场分布和热矢量分布进行了模拟,对比分析了两种散热结构的散热性能,讨论了抽运光斑的参量和金刚石散热片厚度对器件热特性的影响。模拟分析表明:在抽运功率密度较大时,与单面键合金刚石散热片结构相比,双金刚石散热片结构的OPS-VECSEL温升较低,引起的谐振波长差较小,热量向芯片上下两侧散失有利于器件的散热,并且随着抽运功率密度的增大,双散热片结构的散热优势就越明显;当上部金刚石散热片的厚度为500μm、下部金刚石散热片的厚度在300～500μm时可以实现很好的散热效果。     

A 170 J electron beam pumped XeF(C→A) laser

A pulse output energy of 170 J has been achieved from an XeF(C→A) laser system, pumped by a pair of counterpropagating, three-meter-long electron beams. This represents a record for all types of pumping, for this excimer system. Energy was extracted from a volume of ~100 L, using a free-running stable oscillator. No evidence of laser oscillations on the competing XeF(B→X) transition was observed. Within the extraction volume the laser gas was pumped at a rate of 140 kW/cm³ (time average value), for a period of 1.7 μs. The optical cavity was folded, giving a gain length of 6 m. The optical pulse duration was 0.8 μs (full width at half maximum), and the observed flux buildup time of ~1 μs was consistent with modeling and a measurement of the net gain. The specific output energy was 1.7 J/L which is comparable to that achieved in previous, small scale experiments at somewhat higher pump rate. The results confirm the volumetric scalability of the electron beam pumped XeF(C→A) laser system to high output energy per pulse, and the feasibility of operating this system at a low electron beam pump rate which relaxes constraints on the design of the electron gun and pulse power subsystems in a high output energy device. Means for extending the laser pulse duration and increasing the output energy of the specific test device are discussed. An output energy of ~1000 J is projected for an optimized gas cell width, for full size resonator mirrors, and with injection     

半导体光放大器(SOA)皮秒增益和折射率非线性的数值模拟

从速率方程出发 ,采用分段模型对半导体光放大器 (SOA)的皮秒增益和折射率非线性进行了数值模拟 ,具体分析了注入光脉冲引起的载流子浓度的变化、输出光脉冲时域波形的畸变、注入光脉冲引起的增益和位相变化 ,以及输出光脉冲上的频率啁啾。     

RTD多值逻辑(MVL)电路

RTD具有双稳和自锁特性,用RTD构成电路可节省大量器件,这一优点在构建多值逻辑电路(MVL RTD)时显得尤为突出。在引用"遏止"概念的基础上介绍了几种典型的MVL RTD电路,包括多幅输入脉冲信号具有选幅功能的文字逻辑门、能提供三个不同电平输出的三态反相器、将一输入斜坡电压信号变成脉冲输出信号的折线量化器等电路;用"遏止"概念分析了异或门电路的工作原理。     

Time-Delay Limits Set by Dispersion in Magnetostatic Delay Lines (Short Papers)

Analysis and experiments show the extreme dispersion of magnetostatic delay lines. A suitable parameter to characterize the amount of dispersion present has been found to be the maximum output energy contained in a time interval equal to the input pulse duration. The time occurrence of this maximum value gives a convenient measure of the group delay. The pulse shape and energy content versus delay have been determined both theoreticaly and experimentally for axially magnetized circular rods. The results show that delays beyond two to three times the input pulse duration cannot be obtained with more than 50 percent of the output energy contained within the original pulse duration.