光束

The method utilizes an optical device which consists of polarization control elements and polarization beam splitting pieces for realizing the multi-switching of polarization or non-polarization light; in a position sequence, one polarization beam splitting piece is arranged on a main optical path at the back surface of each polarization control element, thereby commonly constituting a 'single-pole double-throw' optical switch with a controller; the controller changes the polarization state of input light beams by driving the polarization control elements according to the control logic, and the input light beams are switched to any one path on an output channel through the polarization beam splitting pieces, thereby completing the designated optical information processing function.

利用偏振控制元件和偏振分束片两种光学元件组成的光学装置实现偏振或非偏振光的多路切换；在位置序列上，每个偏振控制元件后面主光路上放置一块偏振分束片，并和控制器共同构成一个'单刀双掷'光开关；控制器按照控制逻辑驱动偏振控制元件改变输入光束的偏振态，并通过偏振分束片将输入光束切换到输出通道上的任何一路，来完成指定的光信息处理功能。

Then based on the second-order moment method, the closed-form expression of the beam width is obtained, and the beam waist width and waist location for elegant cosh square Gaussian and Sinh square Gaussian beams are also deduced.

基于二阶矩定义，分别推导了复宗量双曲余弦平方-高斯光束和双曲正弦平方-高斯光束的光斑尺寸、束腰宽度及其位置，并对结果作了详细的分析和讨论。

The effects of theFresnel number, spherical aberration coefficients and the beam orders on the beamquality were discussed in detail.

详细讨论了透镜系统的菲涅尔数、透镜球差系数以及光束阶数等参数对光束质量的影响。

It is found that topological charge of vortex beam influences the interference pattern, i.e., by compared with the straight interference pattern of plane wave, the interference pattern of vortex beam is shifted in the transverse direction as we look from the top of the interference to the bottom, and the magnitude and direction of shift are related to the topological charge.

详细介绍了涡旋光束的拓扑荷数对干涉条纹分布的影响。发现同平面波的竖直干涉条纹相比较，涡旋光束的干涉条纹，从顶部向底部看去，沿着横向出现移动，并且移动的大小和方向与拓扑荷数的取值有关。

As for top-hat beam and transmittance of 0.1-1.0 of Gaussian beam intercepted aperture, they were measured to transmittance curves of Z-scan.

但由于实验过程中得到的高斯-贝塞尔光束不易加以确认，所以在实验上利用灵敏度较高的top-hat 光束进行测量。

When the diameter of the arranging circle is less than 5 times of the radius of a unit laser, over 90% of the power will drop into the 86.5% power circle of the unit laser.

结论指出适当选择单元激光器的排列间距可以控制能量的集中程度，甚至使合成光束的能量集中度优于原单元激光器产生的高斯光束。

Firstly, the optical structure of the measurement region of the dual beam laser Doppler velocimeter is derived exactly based upon the wave function of Gaussian beam.

首先从高斯光束的波动方程出发，推导出双光束激光多普勒测速仪相干区域的光学结构及随被测体一起运动的微粒所散射的光波函数。

The basic theory of this design is The Lambert Laws that the logarithm of the radio of the energy of a primal ray and the energy after this ray though a equable material is direct proportion with the thickness of the equable material,and so do the coefficient that the equable material absorpt with the ray.

理论基础是朗伯定律，即通过某一均匀截止前后光束的光能比的对数与介质的厚度成正比，与介质对光束的光能的吸收系数成正比。

The beam quality of a LD pumped Nd∶YAG laser is measured with CCD camera system. The background characteristics of the CCD system and the influence of the size of integral box upon measurement results are investigated. The following conclusions can be derived form experimental results:(1) Background is strongly depend upon exposure time and pixel binning,while temperature has an ignorable effect upon it,whether with or without ambient light.(2) A 5%-cut is the minimum value in order to get a reasonable result.

采用CCD系统实验测量了LD泵浦Nd∶YAG激光器的光束质量参数，研究了CCD系统的背景噪声特性和积分区域选取对光束质量参数测量的影响，从实验数据中得到以下结论：（1）在有、无背景光两种条件下，背景记数强烈地依赖于曝光时间和像素的合并，温度影响可以忽略不计，（2）为获得M2合理的测量结果，至少要选择5%积分区域。

Based on polarization state conversion, a technique for coaxially coherent combination of laser beams is introduced.

基于偏振转换原理，提出了一种相干光束同轴合成技术，多束激光可以同轴耦合为一束激光，具有较高的合成效率和良好的光束质量。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。