基于自适应遗传算法部分相干光整形位相板的优化设计

基于自适应遗传算法,对部分相干光整形的相位板做了优化设计.以高斯-谢尔模型(GSM)光束为例,推导出远场光强的解析表达式.最优化设计的位相板能将GSM光束变为平顶光束.数值计算例表明空间相干性对光束整形效果的影响.与已有工作相比较说明自适应遗传算法用于部分相干光整形的优点. 关键词： 自适应遗传算法 光束整形 部分相干光 位相板     

Multicomponental Fluorimetric Determination of Aluminium, Gallium and Indium

For the fast characteristics of mixtures of Aluminium, Gallium and Indium the fluorimetric evaluation in the form of complexes with 8-Hydroxyquinoline-5-sulphonic acid is described at selected pH. The highly collinear correlated fluorescent spectra and their first derivation were evaluated under various experimental conditions with the Multiple Linear Regression (MLR), Partial Least Squares (PLS) methods and Kalman filtering. When comparing the results, the PLS gives the least relative prediction errors under optimal conditions, 5.6–15.9% for the concentration range of Al 0.025–0.2 μg cm⁻³, Ga 0.1–0.8 μg cm⁻³ and In 0.1–0.8 μg cm⁻³ in the mixture.     

相位片湍流仿真装置中的激光漂移效应

 为了在内场中开展激光传输特性实验研究,设计了一种基于Kolmogorov谱的随机相位片的大气湍流物理仿真系统,并用该大气湍流模拟仿真系统对激光漂移效应进行了研究。采用光束质量分析仪对模拟传输的光斑图像进行采集和分析,通过比较实际漂移方差与理论漂移方差,验证了该湍流仿真系统模拟和评价光束在仿真传输中的性能。实验分析表明,基于湍流相位片物理仿真系统模拟的光束漂移方差与理论曲线基本一致。     

二元微透镜的位相平衡设计及叠加积分衍射分析

本文用位相平衡设计法设计了优化的二元光学微透镜，这是对Ｄａｍｍａｎｎ阶梯波带片设计方法的一种改进。文中用叠加积分作了二元微透镜的衍射分析，并与Ｄａｍｍａｎｎ法作了比较，计算结果说明本方法的衍射效率及象质都优于Ｄａｍｍａｎｎ法。且能设计更大相对口径（Ｄ／ｆ）。具有任意物象距的二元微透镜。     

介绍几种测定波片位相差的方法

本文提出测量彼片位相差的几种方法，并从原理上作了相应的说明．     

菲涅耳编码孔成象研究

编码孔成象(CAI)是一种高分辨率、高信噪比、高集光效率和大视场的成象技术。可适用的技术领域有:脉冲射线成象、实时图象跟踪、层析摄影术(tomography)等高技术领域本文探讨了CAI技术的一般理论,重点讨论了菲涅耳波带片的编码成象及解码复原的原理、方法、实验及处理结果并指出了实验难点及结果误差。     

ICP-AES内标法测定硅铝钡合金中铝和钡

研究了以电感耦合等离子体发射光谱仪测定硅铝钡合金中铝和钡的方法。考查了方法的线性范围,检测限和RSD等指标,实验表明,方法简便,结果准确。     

Retardation calculation for achromatic and apochromatic quarter and half wave plates of gypsum based birefringent crystal

This paper presents retardation calculations for achromatic and apochromatic half and quarter wave retarders of gypsum based birefringent crystal. The calculations indicate that an achromatic wave plates can be obtained by combining gypsum crystal with KDP, ADP, MgF₂, sapphire and calcite birefringent crystals. The residual variation percentages of retardations as a function of wavelength for gypsum/KDP, gypsum/ADP, gypsum/MgF₂, gypsum/sapphire and gypsum/calcite were found to be ± 1.7%, ± 3%, ± 12.2%, ± 12.0% and ± 7.2%, respectively. To reduce the spectral variation of retardations, a third layer (apochromatic) of birefringet material is added to the aforementioned achromatic wave plates. The proposed apochromatic wave plates are gypsum/KDP/quartz, gypsum/ADP/quartz, MgF₂/ADP/gypsum, MgF₂/KDP/gypsum and gypsum/sapphire/MgF₂. The addition of a third layer has reduced spectral residual variation percentages of retardations of the aforementioned apochromatic designs to ± 0.27, ± 0.33, ± 0.3, ± 0.17 and ± 0.45, respectively.     

Thermal Buckling Analysis of FGM Sandwich Circular Plates Under Transverse Nonuniform Temperature Field Actions北大核心CSCD

Based on the von Kármán geometric nonlinear plate theory, the displacement⁃type geometric nonlinear governing equations for FGM sandwich circular plates under transverse nonlinear temperature field actions were derived. With the immovable clamped boundary condition, the analytical formula for dimensional critical buckling temperature differences of the system was obtained from the solution of the linear eigenvalue problem. Moreover, the 2⁃point boundary value problem of ordinary differential equations was solved with the shooting method. The effects of geometric parameters, constituent material properties, gradient indexes, temperature field parameters and layer⁃thickness ratios on the critical buckling temperature differences, the thermal postbuckling equilibrium paths, and the buckling equilibrium configurations of FGM sandwich circular plates, were investigated. The results show that, with the increases of the thickness⁃radius ratio, the relative thickness of the FGM layer and the gradient index, the FGM sandwich circular plate's critical buckling temperature difference will increase monotonically. Given a fixed radius and a fixed total thickness, the postbuckling deformation of the FGM sandwich circular plate will decrease significantly with the relative thickness of the FGM layer. © 2023 Editorial Office of Applied Mathematics and Mechanics. All rights reserved.     

Estimation of the Refractive Index Change in Glass Induced by Femtosecond Laser Pulses

It is known that local refractive index change occurs when femtosecond laser pulses with extremely high peak power are launched into glass. We focused 130-femtosecond laser pulses of 800 nm into the bulk of glass and examined the shape of the induced refractive index change. We found that the length of the spot of the refractive index change along the optical axis reached about 30 μm despite the diameter being about 2 μm. To estimate the distribution of induced refractive index change, we fabricated Bragg grating by scanning the focused spot and calculated the amount of the change by applying Kogelnik’s coupled mode theory to the measured diffraction efficiencies of the higher order diffracted beams.