原向反射屏剩余发散角测试

 提出了玻璃微珠原向反射屏的剩余发散角概念和测试方法：将激光光束投射到原向反射屏,其反射回的激光光束成像到硫酸纸（接收屏）上。利用相机拍摄不同距离下原向反射屏的成像光斑,得到光斑的图像数据;并处理相应图像数据,计算出剩余发散角。通过实验测得所用的玻璃微珠原向反射屏的剩余发散角为0.447 8°。     

基于多种小波分解方法综合判决的低误报率分布式光纤围栏入侵监测系统

针对相位敏感光时域反射计型分布式光纤围栏入侵监测系统对外界干扰敏感、误报率高的问题进行了深入研究,比较了多种小波提取入侵信号突变特征方法,并提出一种基于多个小波分解结果进行综合判决来降低分布式光纤围栏误报率的方法.实验结果表明,多种小波分解可以分别提取不同层次的突变细节信息,为综合决策提供更完备的信息和条件,比单一判决...     

冷原子介质中基于相干诱导高反射带和高透射带的全光路由控制

以相干诱导光子带隙结构为工作基础,提出了一种可对两个弱光信号的传播路径同时进行动态调控的新型全光路由控制方案。利用描述光波在空间周期介质中相干散射的传输矩阵理论,结合描述单频激光与多能级原子共振相互作用的密度矩阵方程,计算了作为控制媒介的相干驱动超冷原子系综的稳态反射光谱和稳态透射光谱。结果表明,通过改变两个较强相干激光的空间模式、强度和频率等参数,可在探测跃迁共振频率附近建立反射率约为95%或者透射率约为95%的两个特殊频带。对这样的相干诱导高反射带和高透射带进行了实时动态调控,可根据需要引导两个不同频率的弱光信号进入指定的网络通道。该方案很好地满足了在量子信息处理领域对弱光信号进行全光路由控制时的低损耗和低形变要求。     

直线加速器同轴负载材料FeSiAl的电磁参数测试及仿真

 为获得直线加速器同轴负载材料FeSiAl的介电常数和磁导率,基于同轴传输反射法,利用矢量网络分析仪,对同轴负载磁性吸波材料FeSiAl的电磁参数进行了测试研究,同时利用电磁场分析软件Microwave Studio进行了测试仿真。研究表明,测量中加工样品与其夹具之间的装配间隙对电磁参数的测试值存在较大影响,进而制作了不同配比的FeSiAl微粉和固体石蜡混合样品,获得混合样品的稳定测试值。对求取电磁参数等效公式的适用性研究表明,Bruggeman,Looyenga,QCACP公式适用于描述该FeSiAl微粉的电磁特性,最后给出了FeSiAl材料的电磁参数。     

带有反射腔的双频相对论返波管的粒子模拟

 设计了一种带有反射腔的能在X波段实现稳定双频输出的圆柱结构相对论返波管,采用2.5维相对论全电磁PIC粒子模拟软件行粒子模拟研究。仿真结果表明:在输入电压433 kV、引导磁场2.2 T的条件下,实现了9.53,10.09 GHz的双频稳定输出,平均输出功率340 MW,平均功率效率24.1%。     

Effect of substrate temperature on microstructure and optical properties of single-phased Ag20 film deposited by using radio-frequency reactive magnetron sputtering method

Using a radio-frequency reactive magnetron sputtering technique, a series of the single-phased Ag20 films are deposited in a mixture of oxygen and argon gas with a flow ratio of 2：3 by changing substrate temperature （Ts）. Effects of the Ts on the microstructure and optical properties of the films are investigated by using X-ray diffractometry, scanning electron microscopy and spectrophotometry. The single-phased Ag20 films deposited at values of Ts below 200℃ are （111） preferentially oriented, which may be due to the smallest free energy of the （111） crystalline face. The film crystallization becomes poor as the value of Ts increases from 100℃ to 225℃. In particular, the Ag20 film deposited at Ts=225℃ loses the （111） preferential orientation. Correspondingly, the film surface morphology obviously evolves from a uniform and compact surface structure to a loose and gullied surface structure. With the increase of Ts value, the transmissivity and the reflectivity of the films in the transparent region are gradually reduced, while the absorptivity gradually increases, which may be attributed to an evolution of the crystalline structure and the surface morphology of the films.     

Proposal of metal bellows-based fiber Bragg grating accelerometer

A metal bellows-based fiber Bragg grating(FBG) accelerometer is proposed and experimentally demonstrated. The optical fiber(containing the FBG) is pre-tensioned,and the two ends of the optical fiber are fixed directly from the shell to the inertial mass. In this design,the FBG is uniformly tensioned to obtain a constant strain distribution over it. By employing this configuration,the FBG always has a sharp reflection characteristic with no broadening in its reflection spectrum during wavelength shifting. Dy...     

Reflex optical sensor based on dual metal gratings with high angular sensitivity

An interesting reflection phenomenon in a dual metal grating (DMG) structure is studied, which is related to the competition between Fabry-Prot (F-P) resonance effect and evanescent-field coupling effect inside the gap between the two composing single metal gratings. This competition leads to high angular sensitivity in response to the refractive index variation of the sample solution in the gap. A reflex optical sensor with high sensitivity based on DMG for detecting the change in refractive index is proposed and its performance theoretically is discussed.     

Design and analysis of a novel tunable optical power splitter

A novel tunable optical power splitter,with a Y-branch waveguide based on the total internal reflection and a microprism with tunable index refraction,is presented.Numerical simulation of its optical performance shows that a high dynamic range,low optical loss,and relatively low wavelength-dependence can be achieved.This component offers numerous advantages such as ease for fabrication,low cost,and compact size,which are very useful for potential application in integrated optical devices.     

土壤砷含量高光谱估算模型研究

以实验室内测取的土壤反射光谱为研究对象,利用PLSR方法建立反射光谱与土壤As含量之间的模型,通过交叉验证、估算检验建模精度,探讨利用反射光谱估算士壤As含量的可行性.通过比较不同光谱预处理方法、不同光谱分辨率和不同OM含量条件下建模、验证和估算结果.表明,MSC方法可以有效去除散射的影响而取得较好的结果(估算R2=0...