共查询到20条相似文献,搜索用时 468 毫秒
1.
本文从Huygens-Fresnel原理的表式出发,用Fourier-Bessel变换讨论Fresnel波带片衍射场的特征,可以很自然地得到波带片的一系列焦点位置,求得焦平面上复振幅及光强的分布 相似文献
2.
膜溶解富集分光光度法测定微量锰的方法研究 总被引:2,自引:1,他引:1
本文以5-Br-PADAP为显色剂,用WX型纤维素滤膜为富集分离膜测定微量锰。使用乙醇溶解捕集物,Mn-5Br-PADAP在乙醇溶液中最大吸收波长为563nm,表观摩尔吸光系数为9.32×10^4L.mol^-1.cm^-1。锰浓度在0.1-5.0μg/5mL范围内符合比耳定律,该法灵敏度高,操作简便,方法应用于食品,水样中锰的测定结果满意。 相似文献
3.
热稳定法拉第旋转TbYbBiIG磁光单晶及性能 总被引:1,自引:0,他引:1
采用高温溶液法,以Bi2O3/B2O3为助熔剂成功地生长出掺铋复合稀土铁石榴石(TbYbBi)3Fe5O12(简称TbYbBiIG)晶体。晶体外形规则,最大尺寸为7×6×4mm3,X射线衍射分析证实,生长的晶体为TbYbBiIG单相单晶体,扫描电镜能谱分析其组成为Tb2.06Yb0.46Bi0.48Fe5O12。在1.0μm~1.7μm波段测量出晶体法拉第旋转谱和光吸收谱。当λ=1.55μm时,在10°C~80°C温度范围内测得法拉第旋转θF的温度系数为dθF/dT=-2.3×10-2deg·mm-1K-1。研究结果表明,TbYbBiIG单晶体在近红外波段θF约为YIG单晶的3倍,温度系数小,是制作高性能光隔离器的一种好材料 相似文献
4.
5.
6.
点降焦激光等离子体发出的X射线经晶体色散形成均匀的单色X射线源,在此基础上,用单层网格作为衰减膜,得到未经衰减和经过衰减的X射线谱,对无保护膜的SIOF-M5FW软X光底片作了试验性的相对标定,得到了0.91nm波长的特性曲线。 相似文献
7.
本文用280nm脉冲激光光解被Ar和Xe基体隔离的Fe(CO)5以产生配位不饱和的Fe(CO)3。用傅里衰变换红外光谱仪实时监察光解停止后Fe(CO)3和CD的复合,并以Smoluchowski扩散控制反应动力学理论模型求得Fe(CO)3与CO的反应半径为4.0×10^-10m,CO在10K的Ar和Xe基体中的扩散系数分别为2.2×10^-23m^2/s和4.5×±∩^-23m^2/s。 相似文献
8.
5-溴水杨基荧光酮-溴化十六烷基三甲铵荧光熄灭法测定微量钼的研究 总被引:1,自引:0,他引:1
本文报道了在溴化十六烷基三甲铵(CTMAB)存在下,以5-溴水杨基荧光酮(5-BrSAF)作为荧光试剂,用荧光熄灭法测定微量钼的新方法。详细研究了各种条件实验。反应的适宜酸度范围为 0.08-0.24m ol·L- 1 HCl,钼含量在0- 4.0μg/25m L范围内呈线性关系,配合物的组成比为Mo(Ⅵ)∶5-BrSAF∶CTMAB= 1∶2∶2,激发波长为365nm ,发射波长为525nm 。方法灵敏度高,检出限为2.0μg/L。用于样品中微量钼的测定,结果令人满意。 相似文献
9.
采用减小焦线宽度,以使低能泵浦功率密度达到适当值的方法,在“星光”装置上开展了碰撞激发机制X射线激光实验。在泵浦能量约130~180J,焦线宽约80μm,靶面功率密度约10TW/cm ̄2条件下,观察到了类Ne锗23.2nm,23.6nm,28.6nm三条激光线。对有可能实现单色X射线激光的元素Zn,仅观察到类Ne锌26.2nm,26.7nm两条激光线。 相似文献
10.
11.
A theoretical method based on the quantum scattering theory is presented to evaluate the performances of a two-dimensional (2-D) focusing square multilayer Bragg–Fresnel lens. The numerical application results of the square multilayer Bragg–Fresnel lens working at 0.7 nm wavelength (W/Si 25 periods with a double layer thickness of 5.38 nm, the size of the diffraction pattern is about 291×291 μm, the size of the center square in the diffraction pattern is 21.4×21.4 μm, and the size of the smallest square in the diffraction pattern is 0.39×0.39 μm) are given. Our theoretical results are compared with the experimental results of the linear Bragg–Fresnel lens reported by other researchers; an analysis and a discussion are carried out regarding the advantages of an optical system based on the 2-D focusing square multilayer Bragg–Fresnel lens, in contrast to a Kirkpatrick–Baez optical system on the basis of a two-linear Bragg–Fresnel lens. 相似文献
12.
A polarization-independent and high-diffraction-efficiency Fresnel lens is developed based on blue phase liquid crystals (BPLCs). The optically isotropic characteristic of BPLCs is used to produce a polarization-independent Fresnel lens. The small optical phase shift of BPLCs that is induced by the Kerr effect is sufficient for the BPLC Fresnel lens to have high theoretical and experimental diffraction efficiencies of 41% and ~34%, respectively. An electrically erasable memory effect in the focusing diffraction at an electric field E>4.44?V/μm is observed. The electro-optical properties of the BPLC Fresnel lens are analyzed and discussed. 相似文献
13.
Kuniharu Takizawa 《Optics Communications》1981,37(5):345-348
One-dimensional focusing and optical modulation have been achieved using a Fresnel light modulator (FLM) based on a Fresnel lens consisting of Ti-diffused channel waveguides on LiNbO3. By this device, the height of diffraction pattern near the focal point is modulated with an applied voltage while the focusing effect is almost kept. The experimental results obtained from the FLM with 13 zones at 633 nm are as follows: the focal length is 12.4 cm, the full width of beam at half power 47 μm, the half-wave voltage 28 V, the extinction ratio 10.9 dB and the insertion loss 11.6 dB. 相似文献
14.
从动力学原理出发对X射线布拉格-菲涅耳多层膜一维聚焦镜的近似设计理论作了推导,给出了近似方程并对近似理论作了误差分析。同时给出了作者编制的数值化计算机程序系统的设计框图及其设计结果,也给出了多层膜膜系设计结果 相似文献
15.
《Physics letters. A》2020,384(10):126219
Using the coupled waves approach complemented by the time-domain quasi-optical approximation, we solve a 2D diffraction problem which allows to evaluate the eigenfrequencies, quality factors and spatial structures of eigenmodes in planar Bragg resonators with a finite length and width of the corrugated area. We find the values of the Fresnel parameter determined by the geometrical dimensions of the system which allows for efficient transverse mode discrimination due to the larger diffraction losses of the modes with higher transverse numbers. 相似文献
16.
17.
The theoretical and technique results of a 1D focusing linear Bragg–Fresnel optics working at 18 nm X-ray radiation are given in the present paper. A theoretical method describing its optical performances is introduced briefly, the parameters of the diffraction pattern are presented. The preparation of multilayer mirrors, the decision of X-ray absorber layer thickness and the fabrication process of the diffraction pattern are described. The studied results of thermal and chemical stabilities for Mo/Si multilayer structure are shown. Some measured results for the 1D focusing linear Bragg–Fresnel optics are given. 相似文献
18.
介绍了一种全新的轴向线聚焦方案.采用菲涅尔波带片,在实验中产生了沿轴向长为5mm,宽 100μm的线聚焦.光学测量表明,线聚焦轴向强度分布比较均匀.这些参数基本上可以满足激 光等离子体实验的要求.
关键词:
菲涅尔波带片
轴向线聚焦 相似文献
19.
20.
This study demonstrates a tunable Fresnel lens in an azo-dye-doped liquid crystal (ADDLC) film using an interference technique. One Fresnel-patterned green beam using a Sagnac interferometer irradiated the UV-illuminated ADDLC cell, yielding a concentric zone plate distribution with homeotropic and isotropic structures in bright and dark regions of the green interference pattern. The proposed Fresnel lens is polarization independent, focus tunable, and the focusing efficiency of the device can be optically controlled. 相似文献