查询词典 diffraction grating

TE mode diffraction characteristics of surface-relief grating having different symmetrical profiles (rectangular, sinusoidal, triangle, trapezoidal profile) are calculated with rigorous second order vector couple-wave theory, the law of diffraction efficiency as a function of grating groove depth are analyzed: in a specific condition, diffraction efficiency might be close to 100%.

本论文采用严格的二阶矢量耦合波理论计算了矩形、正弦、三角形、梯形等对称面形蚀刻光栅的TE模偏振的衍射特性，分析了光栅的衍射效率随着沟槽深度变化规律。

According to condition of phase resonance of fiber grating F-P cavity, the relationship between fiber Bragg grating period and cavity length for fiber grating F-P cavity has been deduced, which provide a basis for the manufacture of the F-P filter based on fiber Bragg grating.

根据光纤Bragg光栅F-P腔的相位谐振条件，推导了光纤光栅F-P腔的腔长与光纤Bragg光栅常数之间的关系，从而为研制基于光纤Bragg光栅的F-P滤波器提供了依据。

A grating function and a groove function are introduced to determine the structure of a concave grating. Basic ideas for the design of a flat-field concave grating with three stigmatic points are proposed. As a proof of the usefulness of these design approaches, image conditions of the grating with three stigmatic points are developed which concise with other published results and they are more general than those obtained from holographic gratings.

采用与分析三维光栅相类似的级数展开法给出了二维集成凹面光栅的球差、彗差的计算方法，计算中用光栅函数和槽面函数来描述具有任意形状和任意变化周期的光栅，提出了一种具有三个无像差点的平面场型凹面光栅的设计方法，利用该方法推导了三点无像差光栅的成像条件，与文献中用其它方法获得的结果相一致，该结果与全息光栅的成像条件相比，更具一般性。

The numerical calculation shows that the space distibution of the electromagnetic field in each sub-micro-layer changes with the varing transmission depth in the relief grating, the space distribution in each sub-micro-layer is uniformer than that in isotropic grating and the optical parameters of the anisotropic relief grating and the incident beam have a large impact on the space distribution of the electromagnetic field in relief grating and so on.

数值计算表明，光波场光强的空间分布随透射深度的变化而变化，各向异性介质光栅体内光波场的空间分布相对各向同性介质要均匀，光栅材料的性质参数和光束的入射参数对光波场光强的空间分布有较大的影响等。

This paper analyzes the optical characteristics of fiber grating according to the theory of mode-coupling in nonsymmetrical optical wave-guide, which affords the gist for the testing of optical characteristics and tuning characteristics of fiber grating. Moreover, we deduce the linear relationship between reflected wavelength shift of fiber grating and vertical displacement of cantilever beam which the fiber grating is sticked on.

论文根据非均匀光波导中的模式耦合理论，分析讨论了光纤光栅的光学特征，为光纤光栅的光学特性和调谐特性的测试提供理论依据；并根据材料力学原理推导了光纤光栅波长漂移量与侧向位移的线性调谐关系。

The wavelength resolution of the sensing measurement is 0.05nm. A novel FBG Bourdon tube sensor has been constructed, utilizing the pressure mechanic amplify function of Bourdon tube. The measured pressure sensitivity is two orders of magnitude higher than a simple monomode fiber with an in-fiber grating. Especially the pressure sensitivity of the sensor can be determined by changing the parameters of the cantilever beam. Adopting polymer package technique, we coat fiber Bragg grating by using polymer with different mechanic properties. Due to the driving effect of the polymer substrate, the enhanced pressure sensitivity is more than 20 times and 31. 7 times than that of a bare fiber grating. The packaged grating exhibits no significant chirp due to the adoption of special packaging technique.

全部采用国产元器件，成功地研制了掺铒光纤超荧光宽带光源，并将其组装成仪器；设计了利用可调谐FBG滤波器对光纤光栅传感信号进行检测的实验方案，对这一传感检测方案进行了理论分析和实验研究，由于采用了高性能的光电测量系统，传感测量的波长分辨率可达2pm，对应的应变分辨率为1.7με，在此基础上对FBG的波分复用传感特性进行了研究；对比调谐滤波检测技术，对光纤光栅可调谐光源波长检测技术进行了理论分析；采用长周期光纤光栅作为边带滤波器，对光纤布拉格光栅的传感信息进行解调，设计了一种全光纤传感测试系统，其波长分辨率可达0.05nm。

By adjusting the positions and angles of the two DVD optical pick-up heads, the relative distance of the two laser spots can be equivalent to one quarter of the grating pitch. When the grating moves, the surface profile of the grating can be measure directly, in order to obtain the two quadrature sinusoidal signals. Then by counting the zero crossing of these two quadrature sinusoidal signals and calculating the interpolation value of these two quadrature sinusoidal signals, the moving direction and moving displacement value of the grating can be obtained.

采用两个光学读取头，且两个光学读取头共用同一分光镜与同一聚焦物镜，於搭配光路的设计，可使两个光学读取头之光束打入同一聚焦物镜，藉由调整两个DVD光学读取头的位置与角度，使聚焦物镜聚焦的两相近聚焦光点的距离相等於四分之ㄧ光栅尺间距，当光栅尺移动时，可直接量测光栅尺的表面轮廓变化，以获得一组正交的弦波讯号，继而利用讯号四分割与细分割处理，计算出光栅尺之移动方向与移动量。

The diffraction efficiency of a phase grating is compared with that of an amplitude grating with same grating constant.

引 言基于多普勒效应的激光测速、测振技术是 60年代初从流体测速研究发展起来的[1] 。

The main works include: In this thesis, we use Finite Difference Time Domain method to study the relationship between diffraction efficiency, angular dispersion and grating constant, to discuss how the grating figure influence the diffraction efficiency, and to research the frequency spectrum characteristic.

主要工作包括：本文分别在垂直入射和自准直入射（光垂直于光栅刻槽面入射）情况下，采用时域有限差分方法，利用商业数值计算软件OptiFDTD对二维闪耀光栅进行了矢量电磁场数值计算，研究了光栅的衍射效率和角色散随光栅常数的变化情况，研究了光栅形状对光栅衍射效率的影响，还讨论了各种光栅的频谱特性。

At first the frequency spectrum of diffraction light is sampled so as to make holographic grating diffraction discrete in space frequency, namely, in the grating code is included discrete frequency spectrum, which satisfies requirements of human vision.

首先对衍射光的频谱进行采样，使全息光栅衍射的是空间频率不连续的离散光，即在光栅的编码中只包含离散光频谱，且满足人眼视觉要求。

The teacher likes the honeymouthed little girl very much.

老师很喜欢这个嘴甜的小姑娘。

Mr. Notker Bien's interests are traveling, spending quality time with the family and long-distance-running.

诺特卡·柏恩先生热爱旅游，长跑，以及和家人一起共度美好时光。