面向薄膜材料光热特性参数的FPTR检测技术研究

该文提出采用频域光热辐射测量技术(FPTR)对金刚石薄膜的光热特性进行检测。首先,建立调制激光作用于一维有限厚度试件的热波频域响应模型,并搭建光热辐射测量检测系统;其次,采用该试验系统对厚度为200μm、直径为1.5 mm的金刚石薄膜进行频域光热辐射测量技术检测试验研究,得到了调制激光作用于金刚石薄膜的光热动态响应特性;最后,采用反问题求解方法获取金刚石薄膜的光热特性参数。试验结果表明,频域光热辐射测量技术可以对金刚石薄膜进行高精度检测。     

光热偏转薄膜热导测试系统及其应用

根据光热偏转光谱（ＰＴＤＳ）原理，研制成功光热偏转法薄膜热导测试系统，对大量试样进行了测量，结果同文献参考值符合较好，测量重复精度优于５０％，为材料科学有关热性质的研究，特别是有关光热偏转薄膜热导率的研究提供了有力的检测手段，为研制高质量金刚石薄膜提供了依据。     

多点源光热法表征液体的热学性质

1引言 液体物质热物理性质的准确测量一直是物理学领域中的研究热点之一.液体材料在受热时会产生较强的对流和辐射等物理特性,因此采用传统的接触式测量方法不易精确测定液体材料的热学参量.由于光学方法具有快速、非接触式等特性,近二十年来已先后有多种光学方法应用到液体物质的热学参量的表征[1,2],其中较为突出的是利用激光在液体中激发的热栅技术.本文在此基础上,并根据调制多点阵源激光在凝聚态物质中激发调制多点阵热源的光热实验,提出了利用多点源光热法表征液体材料热学性质的方法,建立了相应的理论模型并进行了数值分析.     

固体光声检测的两维理论

本文给出了四层媒质理论模型中有两层具有光吸收特性时，各层媒质中两维交变温度场的严格解，并由此导出目前光声检测中常用的传声器检测，光热光偏转检测，热透镜、光热光位移检测、光声压电和热释电检测中先声信号的理论表达式，使固体光学检测理论更系统化和实用化。     

光子晶体光热调控研究

光和热是人类生存的必需条件,合理调控光与热不仅能使人类的生活更加便利,还可以解决探索太空亟需的难题。以光子晶体为代表的微纳结构,可赋予材料本身所不具备的光学特性,通过对关键材料进行微纳结构化,可以显著提高材料的光热调控性能,满足人类在民生和航天应用的需求。本论文从光热调控原理出发,主要包括4个部分:首先是对构建光子晶体的微球合成、蛋白石结构光子晶体和反蛋白石结构光子晶体的制备以及光谱性能进行简介;其次是介绍以光子晶体为代表的微纳结构在光学特性调控中的应用:光子晶体波段选择性反射的光学特性和仿蛾眼微纳结构的抗反射光学特性;随后依据辐射传热原理介绍微纳结构光热调控在智能热控和智能窗上的应用;并简单介绍国际上热门的微纳结构辐射自制冷的研究;最后结合国内外光热调控的研究现状展望其应用前景。     

基于近场技术的微纳尺度热物性测量系统空间分辨率增强

传统的脉冲激光时域热反射系统通常基于远场光学设计,对于微纳米材料热物性测量的空间分辨率约在3μm～10μm范围,不足以满足先进微电子器件和芯片的热物性测试要求.基于近场光学原理,本文研究了提升时域热反射系统空间分辨率的新颖技术方法,并建立了相应的实验系统.实验获得的微纳结构样品测量数据表明,基于近场技术的时域热反射系统...     

聚光太阳能集热场先进技术综述

聚光太阳能热发电技术因其稳定性、可控性,以及高装机容量成为太阳能热利用方式的重要形式。太阳能集热场的集热效率是影响聚光太阳能热电站发电容量和光电效率的重要因素。针对近期太阳能集热场提高光热转化性能的关键技术,从光学结构、集热器结构以及流体工质3个方面进行综述,总结了先进的集热器优化策略和性能提升技术,并指出相应优化方法的局限性,在此基础上对集热场技术未来的发展提出展望。     

光热协同催化甲烷二氧化碳重整反应研究进展

在光热协同催化条件下的甲烷二氧化碳重整(CRM)反应耦合了光效应和热效应，可在低温下反应生成合成气(CO和H₂),减少碳排放的同时将太阳能转化为化学能储存起来，是实现双碳目标的有效策略之一。催化剂是光热协同催化CRM反应的核心，同时调控热催化活性中心(活性金属)的结构性质和吸光材料(载体)的光学特性以及活性组分与吸光材料的协同作用，使光热协同催化剂的热催化性能及光催化性能同时得到提高，是研发高效光热协同催化剂的有效途径之一。介绍了光热协同催化CRM反应的机理及相关金属催化剂和半导体材料的研究进展，并展望了其未来发展趋势。     

基于光热纳米材料的热信号侧向层析技术研究进展

侧向层析检测(LFA)由于简单、快速、便携、成本低廉等优势在疾病快速诊断筛查领域得到了广泛应用。然而,随着医学检验的发展,传统的LFA越来越难以满足其对高灵敏度检测的需求。许多新型功能纳米材料已被引入LFA作为信号标签来实现其高灵敏度检测,其中基于光热纳米材料的热信号LFA技术具有信号稳定、可探测检测线内所有标签信号、成本低、灵敏度较高等优势,近年来得到了快速的发展。建立热信号LFA的核心问题是用于热信号标签的理想光热纳米材料的开发与应用。本文介绍了光热效应的机制和几种典型光热纳米材料的性能特点,然后综述了近年来基于光热纳米材料构建的热信号LFA及其读卡设备设计开发的研究进展,最后总结了热信号标签材料的评价标准和LFA读卡设备开发改进的方向。希望本文的系统介绍可以助力基于光热纳米材料的热信号LFA技术的未来发展。     

二次反射塔式光热发电技术的发展前景分析

太阳能热发电是可再生的清洁能源,在能源领域越来越受到投资者的青睐。塔式光热发电作为最具发展前景的光热发电形式之一,逐步成为光热发电研发和投资开发的重点,但目前主要是具有一次反射装置的系统,吸热器位于高空,传热介质通过管道将能量输送到地面,过程中热能损失较大,本文从镜场光学效率、吸热器效率、管道效率等方面阐述了吸热器位于地面,太阳光经过两次反射到达地面吸热器的二次反射塔式光热发电系统,是一种具有广阔发展前景的光热发电形式。     

Patterning of multilayer dielectric optical coatings for multispectral CCDs

The development of optical sensors for spacecraft applications requires that all components be as lightweight as possible. One method to reduce the weight of a multispectral optical system is to eliminate beamsplitting optics and multiple detectors by patterning a filter array directly onto a CCD. However, techniques commonly used in the production of these filter arrays result in decreased image resolutions. This can greatly impact the performance of sensors used for applications such as planetary probes. To address this issue, we have studied the patterning of multilayer dielectric optical coatings in a small scale, two dimensional array, which will allow development of a four color sensor with a resolution one-half that of monochromatic sensors (compared to one-fourth or less for a four color striped array). We have developed ion milling techniques for the preparation of optical filter arrays which are patterned on a scale as small as 7.5 μm, enabling each pixel of a CCD to have its own associated filter. This paper presents details of the fabrication of these multispectral arrays, and discusses problems associated with pixel-sized filters.     

New optical tools for fluid mechanics

Optical flow measurement is the most important non-intrusive technique in fluid mechanics. A second advantage of some new optical measurement techniques is the high resolution in space and time. As a third advantage, flow visualisation also has a special importance in fluid mechanics. The unsteady three-dimensional flow fields need a visual display of experimental as well as theoretical results. Optical visualisation techniques often lead to completely new insights in flow phenomena especially in experiments. Some discoveries which have been made this way are mentioned here.     

Ce dopant segregation in Y3Al5O12 optical ceramics

Ce³⁺-doped YAG garnet optical ceramic have been sintered at the Shanghai Institute of Ceramics in China to characterize dopant distribution in optical ceramics by combining optical spectroscopy and two spatially resolved techniques as imaging confocal microscopy and transmission electron microscopy. A strong Ce³⁺ segregation and spatial variations of content between grains and grain boundaries has been confirmed by quantitative data obtained by TEM microscopy. This observation is another evidence of the inhomogeneous Ce³⁺ distribution across grain and grain boundaries in optical ceramics comparable to that of Nd³⁺ ions in YAG ceramics. These results correlate well with low segregation coefficients of Nd³⁺ and Ce³⁺ observed in the garnet crystals grown from the melt and/or flux.     

Progress in the room-temperature optical functions of semiconductors

Optical functions of a specific semiconductor in a particular wavelength region are often needed in optics and optoelectronics research. Basic optical properties of some materials are available in handbooks, but recent advances in the experimental techniques for growth, sample preparation and determination of optical functions, as well as theoretical advances in modeling the optical functions, prompted demand for a review of the state of the art of the optical functions of some important semiconductor materials. This paper gives an overview of the experimental methods for the determination of optical functions in the 1–6 eV spectral range and the available models for calculating the optical functions. Also, the paper summarizes the progress in the study of optical functions of several important semiconductors such as GaP, InP, InAs, GaSb, InSb, AlSb, Al_xGa_1−xAs, Hg_xCd_1−xTe, Si_xGe_1−x, GaN, InN, AlN, 6H–SiC, and ZnO. Besides discussing the available data and expected positions of optical transitions, the paper focuses on the model of the dielectric function which allows reproducing accurately the experimental dielectric function values for all the materials considered here.     

光学元件检测技术的研究

介绍了光学非球面加工精磨阶段和抛光阶段的检测技术、柱面镜面形的测量方法、超高精度球面面形的测量方法和光学元件参数的高精度测量技术。     

Determination of optical constants and inhomogeneity of optical films by two-step film envelope method

A simple two-step film envelope method has been proposed to determine the optical constants and small inhomogeneity of the optical films, which uses maximum envelopes and minimum envelope of the normal incidence transmittance of the two-step film. The two-step films were prepared by stopping the deposition process in the middle of the designed sputtering time, and then, after a full cooling down to room temperature, repeating the same deposition process again to complete the whole preparation of the films. The optical constants of Nb₂O₅-TiO₂ mixed films were calculated by two-step film envelope method and traditional envelope method. The experimental results demonstrate that the average refractive index and extinction coefficient calculated by two-step film envelope method are more accurate than those calculated by the traditional envelope method.     

GaGeTe films as phase-change optical recording media

Ga₂₀Ge₃₀Te₅₀ thin films deposited by vacuum evaporation on various substrates have been studied for their structural and optical properties. The as-deposited amorphous films were crystallized by thermally annealing them. The optical constants of the amorphous films indicate semiconducting behaviour (n> k). The optical bandgap (E_g) determined from Tauc's plot is 0.7 eV. The change in reflectance on crystallization has been utilized to obtain maximum optical contrast by optimising the thickness of the film.     

基于光学小波变换的机器人视觉传感器设计

针对视觉系统处理速度慢的问题,利用光电信息技术设计出基于光学小波变换的机器人视觉传感器。该传感器用4 f光学处理系统实现光学小波变换滤波,以计算机编程加载滤波器,因此兼有光学信息处理的二维、高速、并行和大容量的优点,以及计算机控制灵活的优点。图像特征提取仿真实验结果表明:效果理想,处理速度快,方案可行。     

Ultrafast optical nonlinearity of titanylphthalocyanine films

The optical properties of titanylphthalocyanine (TiOPc) thin film fabricated by physical jet deposition technique were investigated by using absorption, femtosecond (fs) optical Kerr effect (OKE) and fs pump–probe techniques. The third-order nonlinear optical susceptibility of TiOPc film was measured to be 3×10⁻¹⁰ esu. The OKE response of TiOPc films shows a decay process with subpicosecond time constant, demonstrating that the excited state of TiOPc molecule has little contribution to the photo-induced birefringence. From the fs pump–probe experiment, a complicated decay behavior with three decay components was observed, which originates from the contribution of exciton–exciton annihilation process, the enhanced intersystem crossing process and the relaxation of the triplet state.     

Investigation of PLC bands with optical techniques

The Portevin–Le Châtelier effect is an interesting phenomenon that afflicts the deformation working of ductile alloys. Characteristic of this effect are the so-called PLC bands, regions of concentrated deformation that usually follow each other in a regular manner. An optical extensometer is here presented as a new measurement set-up for the investigation of these PLC bands. The optical extensometer has been employed during tensile deformation of Al–3wt.%Mg specimens and the propagation of type-B PLC bands has been detected and its velocity measured. A real-time analysis of data has been realized up to 250 scans/s, it permits to locate a deformation as soon as it emerges. This will soon make it possible to track their propagation by means of an optical sensor.