透射光栅

A new type of geophone is presented,based on the narrow band transmission and free of back reflection features of long period fiber grating.

基于长周期光纤光栅能透射特定波长的性质，以及其无后向反射的优点，提出一种新型的长周期光纤光栅地震检波器系统。

Based on Kogelnik's one-dimensional coupled-wave theory and dispersed Fourier transform, the diffractive characteristic of two pieces of volume phase gratings, which are cascaded and having orthogonal grating vectors for the continuous-wave laser beam, is analyzed.

利用Kogelnik一维耦合波理论，以及离散傅里叶变换，分析光栅矢量相互正交，且串联级联放置的两透射型体相位光栅对空域任意分布的连续激光光束的衍射特性；讨论其对入射光束的空间低通滤波性能，并具体模拟其对畸变高斯光束空间低通滤波的效果。

The fabrication of transmission gratings with the grating constant of 2.5μm and 5μm is studied in ZK6 and LaF2 glasses at the machining speed of 400μm/s by using femtoscond laser with the peak intensity of 2.7×10~(13)W/cm~2, and the diffraction patterns of the grating are presented with a semiconductors laser at 650 nm.

在加工速度为400μm/s、激光的峰值功率密度为2.7×10~(13)W/cm~2时，在ZK6玻璃和LaF2玻璃内制备出光栅常数为2.5μm和5μm的透射式衍射光栅，并在650nm的半导体激光照射下获得了光栅的衍射图样。

A transmission grating with an area of 1 mm × 1 mm, a pitch of 300 nm, and a gold thickness of 1 μm for X-ray imaging and microscopy is successfully fabricated by combining electron beam lithography, X-ray lithography, and electroplating.

利用电子束光刻、X射线光刻和微电镀技术，成功制作了面积为1 mm×1 mm，周期为300 nm，金吸收体厚度为1 μm的用于X射线显微成像的透射光栅。

The principle of the method is as follows: The method employs a transmission grating plate placed over a sample surface at a small distance h. According to diffraction theorym an incident light wave is divided into both reflected and transmitted diffraction waves at the grating plate.

该方法的原理如下：该方法采用了透射光栅放置在一个小的距离超过每小时板样品表面据衍射theorym事件光波分为既反映和传播的格板衍射波分歧。

With given parameters of the fiber grating, the transmission spectrum of the long-period fiber grating was obtained by simulation with Matlab. As a result, the position of the resonant wavelength of the long-period fiber grating is decided by the grating′s period. The attenuation changes with the length and refractive index of the grating.

在设定的光纤光栅参数条件下，通过Matlab进行模拟得到了最终需要的长周期光纤光栅透射谱，并由此得出：长周期光纤光栅谐振波长出现的位置主要由光栅的周期决定，损耗大小可以通过调节光栅长度和折射率来实现。

Higher order contributions in the spectral radiation standard and metrology beamline were researched using transmission grating and IRD AXUV100G photodiode detector.

采用自制的840/mm金膜自支撑透射光栅和美国IRD公司的AXUV100G光电二极管探测器，定量研究了光谱辐射标准和计量光束线在5-140 nm波段的高次谐波。

Beginning with wave equation, the paper has deduced the propagation of gauss pulses in single mode fiber and fiber grating transmission compensation. The characteristics of cascaded phase-shift gratings are discussed by numerical simulations of coupled-mode theory and T-matrix method. The experimental works and measurement results are shown in this paper. On the other hand, we have introduced the basic theory of EDFA and figured out the characteristics for EDFA at different conditions by numerical simulation. Some experimental results for EDFA are also presented here. In this article, you can find the influence on Optical Fiber Amplifier by Gain Tilt, especially, the negative effect on CSO in CATV transmission system.

论文首先从波动方程入手，对高斯脉冲在单模光纤中的传播演化及光纤光栅透射补偿进行了详细的研究；较系统地介绍了光纤光栅的耦合模理论，并将传输矩阵计算法用于计算级连相移光纤光栅的光学特性；重点介绍了作者在光纤光栅刻制及特性测量方面所做的一些实验研究工作；较系统介绍了EDFA的基本理论，计算出各种条件下EDFA的光学特性，并进行了一些实验研究；综合分析光纤放大器对光纤传输系统的影响，特别分析了光纤放大器增益不平坦对光纤CATV系统中CSO恶化的原因及其解决方法，并研究了光纤布拉格光栅在稳定980nm泵浦源输出功率和输出波长方面的应用；结合一个基于光纤光栅和光纤放大器的光纤用户接入网方案，对光纤用户接入网的若干问题进行了理论与初步的实验研究。

Additionally, we analyzed the thermal-decay rules of LPGs. We use temperature-compensating package to reduce the sensitivity of temperature of LPGs. At the end of this paper, we summarized the key technologies required during practical application of LPGs, During this paper, we obtained some inventional results as follow: 1. We deduced waveguide modes of single and many mode fibers by use of Maxwell equation.

论文工作期间，主要取得了以下几方面的成果：一、我们利用Maxwell方程，推导了单模和多模光纤的导波模式，同时利用耦合模原理，简要推导了反射式光纤光栅的模式场分布及相应的模式特征方程；采用弱导光纤近似理论，严格推导了透射式长周期光纤光栅的模式场分布，得到了光栅周期与光波长间的对应关系，这是分析长周期光纤光栅光谱特性的有力工具。

Analytical formulae are presented for the first time to describe the shift in the resonance wavelength of LPG in response to etching of the fiber cladding or a change in the external refractive index. The accuracy of the formula is confirmed by comparision with numerical simulations and experimental results. We demonstrated that the resonance wavelengths of an etched LPG are more sensitive refractive index than those of an unetched grating. The bending properties of long period fiber grating written in different type fiber are studied experimentally. The transmission peaks and the central wavelength of LPG change with the bending of the fiber. A new peak appears at the shorter wavelength when the fiber is being bent. The changes of the peaks are different for different photosensitive fiber. Those properties have broad application foreground in fiber sensors and tunable filters.

分别从理论和实验上对长周期光栅的折射率特性以及光纤包层半径对长周期光栅特性的影响进行了研究，首次给出了描述光纤包层半径腐蚀和外界折射率改变与长周期光栅共振波长关系的理论表达式，实验与理论和数据模拟的结果很好符合，利用腐蚀光纤包层的方法可以有效地提高LPG的折射率灵敏度；对不同光纤中写入的长周期光栅的弯曲特性进行了实验研究，LPG的透射峰形状及其中心波长随光纤弯曲而发生变化，并且随着弯曲将在短波方向出现新的透射峰，其透射峰的变化规律因所用光敏光纤的不同而不同，这一特性在光纤传感和可调谐滤波器方面有重要的应用前景。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了