激光器

Based on large aperture Nd∶YAG slabs and dichromatic coatings, a high-efficiency V-shaped active-mirror laser was designed, which was composed of four modules with two large-aperture Nd∶YAG slabs in each module.

基于大口径片状Nd∶YAG介质，采用双色膜技术设计并研制了高效率V形有源镜激光器。该激光器有四个模块，每个模块包含两片大口径Nd∶YAG片状介质。

A tunable Diode laser was used to probe gain spectra of a supersonic COIL.

用小型亚音速氧碘激光器做探测光源，逐点测量超音速氧碘激光器的小信号增益二维空间分布，最大增益为1.1×10〓cm〓。

The ability to have a direct modulation is different from other laser diode laser an important characteristic.

4具有直接调制的能力是半导体激光器有别于其它激光器的一个重要特点。

And after measuring the Doppler shift of scattered light, the winds speed can be calculated.

在本文中，分别介绍了基于CO_2激光器的相干测速和基于1.55μm光纤激光器的全光纤相干测风两种实验系统。

The computer separately connects and controls the I/O end and A/D converter; the I/O end connects and controls the X, Y axis driving circuit and the semiconductor laser; the X, Y axis step-by-step driving circuit connects and controls the X, Y step-by-step electrical machines to control the dimensional platform; the beam of the semiconductor laser passes through the focusing drawtube with 0.1mm diameter to form the facula with the diameter less than 0.1mm; the facula irradiates on the detector surface of the XY dimensional displacement platform to produce the corresponding electric signals; the detector surface connects the A/D converter through the amplifier; the electrical signal is amplified and is converted into the data signal by the A/D converter and is sent to the computer for processing.

由计算机分别连接并控制I/O端口和A/D转换器，I/O端口分别连接并控制X、Y轴步进电机驱动电路和半导体激光器，X、Y轴步进电机驱动电路分别连接并控制X、Y轴步进电机，从而控制二维位移平台，半导体激光器的光束经过设有直径0.1mm小孔的聚焦镜筒形成＜0.1mm直径的光斑，光斑照射于设在XY二维位移平台上的探测器表面使其产生响应的电信号，探测器表面经放大器连接A/D转换器，电信号经放大器放大后，由A/D转换器转换为数据信号送计算机处理。

So the frequency of pulse drive mode amounts to the frequency of external signal, and the operate frequency of driver should be below the frequency of MOSFET.

本论文所涉及的工作对半导体激光器的广泛应用具有积极意义，它解决了半导体激光器应用中存在的关键问题。

In the first part of the paper, the light source and its light output measurements are described. The second part is concerned with some investigations of ruby and Nd-doped glass laser s, pumped with electrodeless discharge tubes.

文章的前一部分包括光源的装置及特性的测量等，第二部分的内容为利用这种光源作红宝石与钕玻璃激光器的激发光源时，对于激光器的光输出特性的研究结果，其中包括阈值的测定，尖峯的观察、单模振荡和规则的阻尼振荡等。

In the first part of the paper, the light source and its light output measurements are described. The second part is concerned with some investigations of ruby and Nd-doped glass lasers, pumped with electrodeless discharge tubes.

文章的前一部分包括光源的装置及特性的测量等，第二部分的内容为利用这种光源作红宝石与钕玻璃激光器的激发光源时，对于激光器的光输出特性的研究结果，其中包括阈值的测定，尖峯的观察、单模振荡和规则的阻尼振荡等。

Laser Bias Low - The laser bias current is getting low. Means end of life of the device.

激光器偏流低－激光器的偏流正变的越来越低，意味着器件寿命的终了。

The vapour and plasma ignition times of the target are got based on the equation of heat conduction and cascade model. We suppose that the plasma is ignited when 210 generations of new electrons are born in vapour generation time. The influence of temperature on the thermodynamics and optics parameters of material also have been considered in the model. The resulting theory has good agreement with the experiment and overseas report. A blade method to measure the laser spot is given in this paper with validation and error analysis. The plasma threshold of metals in atmosphere and water ambients both are diagnosed with the light deflection and piezoelectric transducer. A Q-switched pulsed Nd:YAG laser operating at infrared (1064nm), visible(532nm) and ultraviolet (355nm) wavelengths has been used. Al、Fe、Cu are used as targets and get a similar results with both method. Theoretical and experimental analyses are applied on the influence of wavelength on the threshold have been done, both of which have shown that the plasma threshold of metals decrease as the laser wavelength increases; The plasma threshold of metals are higher in water than in air and the pressure of the shock wave in water is five times higher than in air.

从热传导方程和雪崩电离机制出发，假设当电子增值2~(10)倍时，考虑了温度对材料热力学和光学参数的影响时，得到了气化和等离子体点燃的时间，利用该模型进行计算得到的结果与国内外报道及自行通过实验测得的阈值基本一致；提出了利用刀刃法测量激光光斑面积的方法，并通过实验进行了验证和误差分析；利用光偏转装置和压电换能器分别对空气和水中金属等离子体点燃阈值进行了实验诊断，激光器均为调Q—YAG激光器(波长1064nm，532nm，355nm，脉宽10ns)，靶材分别为Al、Fe和Cu，两种测试方法得到的等离子体点燃阈值基本一致；本文从实验和理论计算两个方面讨论了波长对等离子体点燃阈值的影响，均得到了等离子体点燃阈值随着波长的增加而减小的结论；对空气中和水中不同环境下金属等离子体的点燃阈值进行了比较研究，得到了金属在水中的等离子体点燃阈值比空气中的大，且水中产生的冲击波的压强是空气中的5倍左右的结论。

If you are unfortunate enough to the lovelorn, please tell me, I will help you out, really, please contact me!

如果你不幸失恋了，请告诉我，我会帮助你摆脱困境，真的，请联系我啦！

China's plan to cut energy intensity by 20 percent and pollutant discharges by 10 percent between 2006 and 2010 is a case in point.

中国计划在2006年到2010间降低20%的能源强度和减少10%的主要污染物排放，就是一个这样的例子。