光束

When the ratio of signal Airy disk radius to local oscillator Gaussian 1/e field radius at focal plane is 1.71, maximum heterodyne efficiency of 81.45% can be obtained.

当焦平面上爱里斑半径与本振高斯光束光腰半径之比为1.71时，有最大外差效率81.45%。

Li Hui has repeatedly expressed his insecurities towards life through rays of laser lights; the smoky ambience created by the fogger stressed the tensions one can feel in an abstract space.

李晖不断透过雷射光束表达他对生命的不安全感；烟雾缭绕的氛围加深了一个人在抽象空间中所能感受到的紧绷感觉。

Study of propagation properties of apertured super-Gaussian beam by using the Fourier series expansion .

用傅里叶级数展开法研究受光阑限制的超高斯光束的传输特性。

By using the Fourier series expansion, approximate analytical propagation equations of laser beams through a paraxial optical ABCD system with different apertures are derived.

用傅立叶级数展开法研究光束通过有光阑限制的近轴ABCD光学系统的传输特性，导出了光阑透射率函数不同时的传输公式。

With a CCD camera and a frame grabber to capture the laser spot, the digital image is transferred to special software for further processing, the amount of the laser spot drift can be achieved. The amount of the drift in X direction, Y direction and in spatial angle can be obtained through geometrical optics.

它采用CCD摄像头和图像采集卡采集激光器输出光斑，通过专门软件对数字图像进行处理，得出光斑漂移的大小；另外，利用几何光学方法得到了激光光束在X方向、Y方向以及空间立体角上的漂移大小。

Dammann, are based on Fraunhofer diffraction and are one kind of the most effective elements to generate array for high diffraction efficiency with good uniformity.

Dammann提出的达曼光栅因其效率高，光束分布均匀性不受入射光强分布影响等优点，成为目前最有效的分束器件之一。

Methods On the symmetrical plane of the double-Gauss lens with 1:1 magnification,the Fraunhofer diffraction of the object surface could be formed.

方法在双高斯1：1制版镜头的对称面上形成物面的夫朗和费衍射，并使物面与茶形散斑屏重合，使得各物点均以狭缝状的光束通过透镜组在记录介质面成像。

Free electron laser is a novel coherent light source. It has a wide tunable ability, a high output power, and a high quality light beam.

自由电子激光是一种新型相干光源，它的激光频率在很宽的范围连续可调谐，输出功率高，具有良好的光束质量。

Based on Fresnel Kirchhoff diffraction integral equation, a mathematical model on the diffraction of nonlinear optical media to Gaussian beam is established.

从菲涅耳基尔霍夫衍射积分公式出发，建立了非线性光学介质对高斯光束的衍射模型，通过数值积分，得到了与实验现象符合的计算结果。

The spatial propagation properties of output annular laser beam from an unstable resonator are studied based on Fresnel diffraction integral.

本文从菲涅耳衍射积分公式出发研究了激光器非稳腔输出环状光束在空间的传输规律。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。