激光

Four laser beams as 40K and 87Rb cooling and repump lights are obtained by using acoustic optic modulators to offset the frequencies from the three ECDL lasers. Four light beams with the different frequencies are injected into four slave lasers for injection locking, then Rb cooling light, K cooling light and K repump light are injected into a semiconductor tapered amplifier in a master oscillator-power configuration.

采用三台外腔光栅反馈半导体激光器、四台注入锁定激光器和一台半导体激光放大器组成激光系统，三台外腔光栅反馈半导体激光器通过声光调制器产生四束光，分别作为40K和87Rb原子的冷却光和再抽运光，四束不同频率成份的激光分别注入锁定四台从激光器，然后Rb cooling光、K cooling光和K repump光再同时注入半导体激光放大器进行放大。

The laser diode system is composed of three external cavity diode lasers and four injection diode lasers and a tapered amplifier. Four laser beams as 40K and 87Rb cooling and repump lights are obtained by using acoustic optic modulators to offset the frequencies from the three ECDL lasers. Four light beams with the different frequencies are injected into four slave lasers for injection locking, then Rb cooling light, K cooling light and K repump light are injected into a semiconductor tapered amplifier in a master oscillator-power configuration.

采用三台外腔光栅反馈半导体激光器、四台注入锁定激光器和一台半导体激光放大器组成激光系统，三台外腔光栅反馈半导体激光器通过声光调制器产生四束光，分别作为40K和87Rb原子的冷却光和再抽运光，四束不同频率成份的激光分别注入锁定四台从激光器，然后Rb cooling光、K cooling光和K repump光再同时注入半导体激光放大器进行放大。

The power density inferior to the threshold may leads a decline of solar cell output, which is restorable and temporary. The consequential ablation damage is caused by heat effect of laser.

在低于某一激光功率密度阈值时，激光照射引起的太阳能电池输出下降是暂时的，是可恢复的，低功率密度激光对太阳能电池的干扰和破坏主要是激光引起的热效应。

A high resolution ranging method is described utilizing a novel modulated waveform, hereafter referred to as coherent burst modulation. The laser is sinusoidally modulated for a brief period of time and then is off for a much longer period of time.

在脉冲相位式激光测距中提出采用连续发射的正弦调制脉冲信号提高发射激光的峰值功率以提高测程，但发射激光的平均功率被保持很低保证了发射激光对人眼的安全。

Technology of laser hardening surface of diesel locomotive camshaft using austenite-bainite nodular-iron instead of 20Cr has been systematically elaborated on,which includes a series of measurements such as mechanism of choosing austenite-bainite nodular-iron and it's pretreatment,ascertaining laser technological parameter,spiry laser scanning strip,designing four-motor control devise using microcomputer and so on.

阐述用奥贝球铁代替 2 0Cr制造内燃机车凸轮轴的激光表面强化的工艺过程，其中包括奥贝球铁的选择、激光工艺参数的确定、螺旋激光扫描带、四联动微机控制装置的设计等。研究表明，用奥贝球铁代替 2 0Cr制造凸轮轴，经激光表面强化后，能获得更均匀的硬度分布和更高的硬度值。

The energy spectra of hot electrons have been measured using the magnetic spectrometers, fitted with the LiF thermoluminescent dosimeter which were calibrated using Cs~(137)γ-ray sources, in the interaction of a 130 mJ, 60 fs, 800 nm, 1∶10~(-6), 7.0×10~(17) W·cm~(-2) P-polarized laser incidence on Cu foil target at an angle of 45° with respect to the target normal without any prepulse.

在激光能量130mJ，脉宽60fs，波长800nm，对比度1∶10-6，激光与靶法线成45°夹角， P偏振，靶面激光峰值功率密度约为7.0×1017W·cm-2，无预脉冲的条件下，采用电子谱仪与经γ标准源标定的LiF热释光探测器相配合，测量了飞秒激光薄膜靶相互作用中产生的超热电子能谱。

The old system of laser range finder, which processes laser emission system, laser incepting system and measuring round-trip time of light pulse by separated cell circuit, makes the cost of exploiture expensive, debugging difficult, circuit complex, precision inaccurate, reliability low, bulk and weight great, even without any standard suited gate together with other instruments. Therefore, popularization application of laser range finder is cumbered.

早期的激光测距系统在激光接收机中通过分立的单元电路处理激光发、收信号以测量光脉冲往返时间，使得开发成本高、电路复杂，调试困难，精度以及可靠性相对较差，体积和重量也较大，且没有与其他仪器相匹配的标准接口，上述缺陷阻碍了激光测距系统的普及应用。

The surface roughness of the laser shock peened medium has effect on the high frequency of laser-generated surface acoustic waves. As the impact times of the laser shock peening increase, the surface roughness has little effect on the dispersion of laser-generated surface acoustic waves. From the theoretical curve and experiment curve, it can ...

本文研究的结果，可对研究样品激光冲击硬化后残余应力、晶粒方向改变和错位密度增加分别对激光声表面波色散影响提供了基础，并对利用激光声表面波的色散特性来研究激光冲击硬化材料冲击层材料性质的变化具有一定的意义。

Laser-generated surface acoustic waves are excited by Nd:YAG and the signals are detected by PVDF transducer. The paper discusses laser-generated surface acoustic waves in the smooth and non-laser shock peened medium by using the experimental system.

分别对不同激光冲击硬化次数下样品表面抛光前后的激光声表面波信号进行探测，通过对探测到的激光声表面波信号进行频谱分析，利用相位谱法得到激光声表面波的相速度色散曲线。

The results show that laser-arc welding can achieve full penetration by single-path butt jointing through appropriate parameters; Y shape groove with 8 mm truncated edge can enhance the penetration ability of laser-arc hybrid welding. Low welding speed is good for penetration, however the limitation still exists for hick plates joint. Gap is significant factor of penetration when work pieces is large thickness. The hardness of thick plates joint shows that there is big difference in mold of vertical thermal cycle using laser-arc hybrid welding.

结果表明：通过激光功率等焊接规范匹配，激光-电弧复合焊接能实现20 mm厚板的全熔透单道对接；钝边为8 mm的Y形坡口有助于提高厚板激光-电弧复合焊缝熔透能力；降低焊接速度有利于提高熔深能力；工件厚度较大时，装配间隙对焊缝熔深能力的影响较为显著；接头硬度表明厚板激光复合焊焊缝纵向热循环模式存在较大差异。

Methods: Five patients with parkinsonism or dystonia were assigned to general anesthesia using an modified endotracheal tube.

本实验依照人体实验之相关规定进行，五位患有帕金森氏症或肌张力异常的病人接受神经立体定位手术。

If you can benefit from this book, it is our honour.

如果您能从本书获益，这将是我们的荣幸。