4×2×3阵列式放大器参数测量系统优化设计

采用软边光阑和多级空间滤波器组合技术实现了光束的空间整形和等像面传输，利用Fresnel光束传输计算程序对4×2×3阵列式放大器参数测量系统进行了优化设计，分析了空间滤波器中小孔尺寸对光束波面传输的影响，并对优化设计结果进行了分析和讨论，所用方法和所得结论对高功率固体激光放大系统的设计有应用意义。     

4×2×3阵列式放大器参数测量系统优化设计

 采用软边光阑和多级空间滤波器组合技术实现了光束的空间整形和等像面传输，利用Fresnel光束传输计算程序对4×2×3阵列式放大器参数测量系统进行了优化设计，分析了空间滤波器中小孔尺寸对光束波面传输的影响，并对优化设计结果进行了分析和讨论，所用方法和所得结论对高功率固体激光放大系统的设计有应用意义。     

超高斯光束在超短脉冲激光系统中的传输

 为了增大光束的填充因子及提高放大器的能量转换效率,设计了一种新型的空间4程放大器,该放大器包括四组由凹面镜组成的空间滤波器,它们构成一个全像传递系统。由于有实焦点,放大器置于真空系统中。放大前,入射的高斯光束首先通过一个软边光阑和一个空间滤波器,被整形为高阶超高斯光束,然后在放大器中进行放大和像传递。钛宝石晶体置于各空间滤波器的像面和物面上。实验表明,该放大器结构稳定,可以保持良好的光束质量,远场焦斑达到近一倍衍射极限。     

高功率激光系统软边光阑设计

针对第9路激光系统进行了软边光阑设计。首先编制了第9路激光系统光路传输模拟程序，通过计算“神光”-Ⅱ光路作为验证，以保证程序可用性。在传输模拟程序中，考虑了激光系统各级放大器的增益不均匀性以及增益饱和因素。最后利用这个程序，研究软边光阑各个参数对光束质量的影响，设计适合第9路系统的软边光阑，使系统中光束的填充因子尽可能大，光场调制度尽可能小。     

高功率激光多程放大系统光束传输的计算分析

 报道了高功率激光多程放大系统光束传输的模拟程序, 该程序考虑了放大介质的增益分布、增益饱和、增益恢复系数、介质吸收损耗、B积分以及光阑和空间滤波器等光学元件对激光传输和放大的影响, 并给出了典型的计算实例。     

采用液晶空间光调制器进行激光光束的空间整形

提出采用液晶空间光调制器进行激光束的实时,可调控光束空间整形的新方法,研究了液晶空间光调制器的光学调制特性,用液晶空间光调制器衬时产生的软边切趾光阑与空间滤波器结合,有效地对任意光束进行空间整形,获得光束填充因子高,近“平顶”光强的光束近场分布。     

小宽带光谱色散匀滑光束传输特性研究

利用激光聚变研究中心自主开发的小宽带传输放大软件对小宽带光谱色散匀滑(SSD)光束进行具有"时间、空间、光谱分辨"的传输模拟,研究了SSD光束通过空间滤波器和自由空间的传输特性.给出了时间、空间、光谱的对应分布图,对比分析了SSD光束与非SSD光束的传输效应.研究结果对于合理设计SSD光束的发散角与空间滤波器小孔之间的匹配关系、选择适宜的调制频率,以及选择束匀滑色循环数等都有重要意义,同时对于光路设计特别是细光束自由传输距离的设计具有指导意义.     

激光核聚变装置中基于像传递的激光自动准直技术研究

基于像传递的激光自动准直技术是提高准直准确度、增加稳定性的好方法。本文在理论上用两快速傅里叶变换（ＦＦＴ）分析了准直中基于像传递的近远场信号对图像处理影响。在光束近无场像面上引入十字叉丝并以“神光”装置的某一级空间滤波器为例,计算出光束直径一定时合适的十字叉丝尺寸;最后通过实验确定了基于像传递的自动直技术的具体实现系统。     

神光II升级装置波前传输计算模型与验证

基于衍射理论和神光II升级激光装置的光路结构及光学元件波前像差,建立了激光装置光束波前像差传输计算模型,用以获取在实验中难以取得,但对激光系统设计和安全运行非常重要的变形镜校正面型、放大器动态波前像差、空间滤波器波前像差和焦斑形态等过程数据。利用该模型对激光装置常规运行时的静态传输、变形镜加压静态传输和大能量发射3种状态下的波前传输进行理论分析,计算结果与实验测量相一致,并在此基础上对变形镜未加压大能量发射波前传输进行计算。计算模型可用于指导相关器件的设计,优化激光运行控制模式,有利于提高激光装置输出波前质量。     

拉曼链系统用空间滤波器设计的实验研究

进行了惯性约束聚变（ＩＣＦ）准分子激光拉曼链工程的基础研究工作。为给出拉曼链中所用空间滤波器的设计要求和可靠性,进行了详细的设计实验判断性研究。给出研究过程和结果,并对设计结论和优化方法进行了基础分析。还据实验结果讨论了适用于高功率激光系统的空间滤波器的设计中面临的焦距和滤波小孔孔径选择的不确定性、滤长和光束功率密度对选择小孔的影响等问题。     

Design and application of a laser beam alignment system based on the imaging properties of a multi-pass amplifier

Image relaying is presented as a technique for aligning beams onto mm-sized target of high power laser. On the basis of summarizing the preceeding work on the near-field image relaying of multiple spatial filters,the far-filed image relaying is suggested firstly. The near-field and far-field image relaying properties of multiple spatial filters in laser beams automatic alignment system are analyzed. A geometrical optics approach and an ABCD ray matrix theory are used throughout. The reasonable and optimum scheme for automatically aligning multi-pass beam paths is presented and demonstrated on the multi-pass amplifier system of the SG-Ⅲ prototype.     

钕玻璃高功率激光系统中的空间滤波器的基本研究

本文在阐明多级空间滤波器像传递对改善光束质量作用的同时,对滤波小孔的选择进行了细致的理论探讨和数值计算。并对多级空间滤波器的景深提出了新的观点。对滤波器的精调提出了一套新的实验技术。 关键词：     

用逐次逼近迭代法分析含空间滤波器的多程激光放大系统的逆问题

基于Ｆｒａｎｔｚ－Ｎｏｄｖｉｋ（Ｆ－Ｎ）方程和广义惠更斯－菲涅耳衍射积分，提出了解决含空间滤波器的多程激光放大系统的逆问题的迭代算法，并作了数值计算了，所得的数值计算方法和有关结果可用于高功率多程激光放大系统的设计。     

Compact waveguide bandpass f ilter employing two-dimensional metallic photonic crystals for millimeter to terahertz frequencies

Two-dimensional metallic photonic crystal slabs with square lattice are proposed to be used for the design of waveguide bandpass filters operating in millimeter to terahertz region. Filter characteristics are studied when rod radii and lattice constants are changed. Based on the frequency scaling technique, a series of higher frequency filters has been designed. By using laser drilling and welding processing techniques, a compact waveguide filter embedded in an EIA-WR10 waveguide with central frequency 145.5 GHz and 3-dB bandwidth of 5.26 GHz is fabricated and measured. The measurement data agree well with the simulation prediction.     

Real-time recognition of microscopic phase objects

A method of image enhancement and real-time input of 3-D, microscopic phase objects into a coherent optical pattern recognition system is described. The method consists of directing a low-power laser beam into a microscope objective to produce a real, magnified, coherent image of the specimen under test. The image plane is followed by two successive Fourier transform (FT) planes. In the first FT plane, low and high frequency spatial filters, one of which is photographically produced, are used as pre-processing filters to enhance the image quality. The enhanced signal is imaged from the first FT plane to the second FT plane which contains a matched spatial filter used for specimen identification. The system does not require an expensive incoherent-to-coherent light transducer and in addition, is capable of utilizing both phase and amplitude information from 3-D objects. Examples of results are given.     

Evolution of low-frequency noise passing through a spatial filter in a high power laser system

The theoretical model of spatial noise passing through a spatial filter is established in high power laser system under the small signal approximation. The transmission characteristic for a noise signal passing through spatial filters with different magnifications is analyzed by numerical simulation, according to the actual structure of the high power laser system. The results show that the spatial modulation period of low-frequency noise getting through the pinhole will be proportional to the magnification...     

基于Fibonacci序列准周期结构的小角度低通空间滤波器

利用常规材料构造了Fibonacci序列准周期结构,运用传输矩阵法研究了该结构的空间传输特性,并基于该结构优良的空间传输特性设计了小角度低通空间滤波器.数值模拟结果表明,该小角度空间滤波器的角域带宽可通过改变序列的结构类型和序列数来调谐,其调谐规律为:随着Fibonacci序列F(m,1)中m值的增加,对应空间滤波器的角域带宽减小;随着序列数的增大,对应角域带宽也减小.在调谐的基础上,还可通过改变构成准周期结构的介质折射率参量来精确调节其角域带宽.相比于基于超材料的小角度空间滤波器而言,基于Fibonacci序列的小角度空间滤波器制备更简单,且有望应用于新一代的高功率激光系统中.     

Simple coherent-optical colour encoder

A simple, coherent-optical processor for the production of colour-encoded images from half-tone screened, black and white transparencies is described. Only one laser is used, and the images generated when different diffracted orders and selected by a spatial filter are picked up by a black and white, closed-circuit television system. The screen of the monitor is photographed successively through appropriate coloured filters to produce a colour-encoded image.