Performance of gain-switched all-solid-state quasi-continuous-wave tunable Ti:sapphire laser system

We have made a gain-switched all-solid-state quasi-continuous-wave （QCW） tunable Ti：sapphire laser system, which is pumped by a 532 nm intracavity frequency-doubled Nd：YAG laser. Based on the theory of gain-switching and the study on the influencing factors of the output pulse width, an effective method for obtaining high power and narrow pulse width output is proposed. Through deliberately designing the pump source and the resonator of the Ti：sapphire laser, when the repetition rate is 6 kHz and the length of the cavity is 220 mm, at an incident pump power of 22 W, the tunable Ti：sapphire laser from 700 to 950nm can be achieved. It has a maximum average output power of 5.6W at 800nm and the pulse width of 13.2 ns, giving an optical conversion efficiency of 25.5% from the 532 mn pump laser to the Ti：sapphire laser.     

两台独立飞秒钛宝石振荡器的高精度主动同步研究

对两台独立钛宝石飞秒振荡器的高精度主动同步进行了研究.实验中共采用三套锁相环对它们输出的激光脉冲进行了主动同步控制，最终得到了时间抖动低于30fs的同步精度；由于通过计算机智能监控两台振荡器的相对腔长变动，使得高精度同步维持的时间高达40min.     

在P2P网络下Sybil攻击的研究与防范

P2P网络的自由开放特性使得节点可随意创建身份加入系统，但这也会引发Sybil攻击。文章设计了一种新节点身份的认证方案，提出新节点身份需暴力破解单向函数的计算难题才能加入网络。因此增加了用户创建新节点身份的代价，使得用户无法随意创建身份，从而达到了验证新节点身份的目的，避免系统受到攻击。     

电子信息产业应该成为山西经济增长点的研究

在深入调研基础上，就山西电子信息产业的过去做了深入分析，对今后的发展思路及六个具体项目做了认真的研究，为山西产业结构调整提供决策参考。     

采用视频积累器的对数接收机的检测性能

本文研究瑞利和非高斯型杂波干扰中对数接收机的检测性能。在瑞利杂波干扰中,求出了稳定目标Swerling第一类起伏目标和Swerling第二类起伏目标的这种性能。对数接收机的检测损失通常小于Green推测的损失1/2 logn,但与Hansen确定的渐近损失1.08分贝相一致。Swerling第二类起伏目标的损失在频率捷变应用中是很重要的,在积累脉冲数少而检测概率P_d较高时,该损失可能很严重,而且显然趋近于渐近损失1.08分贝作为下限。为了确定对数接收机的性能,给出了Gram-Charlier级数的累积量的曲线。还给出了确定对数-正态和韦布尔杂波干扰下对数接收机检测性能的曲线。     

关于指数函数与对数函数的教学

指数函数与对数函数的教学是在实指数概念的基础上来进行的,由于指数函数与对数函数之间的紧密联系,所以大纲把指数函数与对数“作为一个单元来看待,并且把指数函数和它的图象与性质”放在“对数定义与对数函数”之前来讲授,我们认为大纲这样来处理有很多优点,它可以使学生在对指数函数新鲜的记忆和认识基础上立即学习对数函数,并在教对数函数中处处可以对照着进行。这样,指数函数与对数函数互为反函数这一点,将更显明和突出。     

光通信用可调谐激光器技术研究发展

可调谐激光器是DWDM系统及未来全光网络中的关键器件,提升了易升级、可重构光网络的智能性和动态性．全面详细地介绍了各种通信用可调谐激光器的类型、结构、特点及调谐原理,描述了多家著名公司推出的可调谐激光器的性能参数,总结了可调谐激光器的研究进展和发展趋势．     

高稳定LD端面泵浦腔内倍频Nd∶YVO4/LBO连续红光激光器

设计出一种能够较好地补偿激光晶体热效应的激光谐振腔,实现了高稳定LD单端泵浦LBO腔内倍频Nd∶YVO4连续红光激光器.当晶体吸收的泵浦功率为24.56 W时,671 nm激光功率达到1.203 W,光-光转换效率4.9%,激光模式为TEM00模.在输出功率为1.08 W时,激光器1 h功率不稳定度为0.52%.     

A Bidirectional, Diode-Pumped, Passively Mode-Locked Nd：YVO4 Ring Laser with a Low-Temperature-Grown Semiconductor Saturable Absorber Mirror

We report the operation of a bidirectional picosecond pulsed ring Nd：YVO4 laser based on a low-temperaturegrown semiconductor saturable absorber mirror. Except for the laser crystal, the six-mirror ring laser cavity has no intra-cavity elements such as focusing lens or mirror. The bidirectional mode locked pluses are obtained at the repetition rate of 117.5 MHz, pulse duration of 81 ps, power of 2 × 200 mW.     

An All-Solid-State Tunable Dual-Wavelength Ti：Sapphire Laser with Quasi-Continuous-Wave Outputs

A high power dual-wavelength Ti：sapphire laser system with wide turning range and high efficiency is described, which consists of two prism-dispersed resonators pumped by an a11-solid-state frequency-doubled Nd：YAG laser. Tunable dual-wavelength outputs, with one wavelength range from 750nm to 795nm and the other from 80Ohm to 850nm, have been demonstrated. With a pump power of 23 W at 532nm, a repetition rate of 6.5kHz and a pulse width of 67.6ns, the maximum dual-wavelength output power of 5.6 W at 785.3nm and 812.1 run, with a pulse width of 17.2ns and a line width of 2nm, has been achieved, leading to an optical-to-optical conversion efficiency of 24.4%.