中红外AOTF前置光谱相机折/衍射混合变焦光学系统

设计了基于AOTF器件的中波红外光谱相机前置变焦系统,针对AOTF器件和探测器的特性,系统采用折/衍射混合设计,用6片透镜即实现了25~300 mm连续12×变焦,并用ZEMAX软件对则汇集结果进行优化和像质评价。结果表明,该光学系统各个波段上在空间频率14 lp/mm处调制传递函数(MTF)值接近衍射极限,能量集中度大于90%。可用于大多情况下中红外光谱成像分析以及中红外的目标探测及识别。     

一种新型农药浓度荧光测量系统的研究

根据声光可调滤波器（Acousto-Optic Tunable Filters，AOTF）的分光原理研制了一种新型的农药浓度荧光俭测系统，系统以高压短弧氙灯为激发光源，以AOTF为分光元件，利用光纤探测传输荧光，采用数据采集卡实现数据接收和A／D转换，由微机进行数据存储和显示，并且利用该系统实现了对西维因农药浓度的荧光持性的测量。结果表明：系统测量光谱范围为230nm～750nm，光谱分辨率为10nm，在激发波K319nm、荧光波长650nm、西维因溶液浓度为0．0～120．0μg／L时系统具有较好的线性关系，线性相关系数r为0．9991，该系统达到了荧光检测的指标。     

一种以AOTF为核心的农药荧光检测系统

提出了一种将 AOTF 技术用于农药含量检测的荧光光谱系统。该系统分别采用以α-Quartz,TeO2 晶体作为声光介质的激发和发射色散元件 AOTF,以高压短弧氙灯为激发光源,利用光纤探测并传输荧光,由数据采集卡进行数据接收和 A/D 转换。该系统通过声光调制产生单色光,由超声射频的变化实现光谱扫描,没有机械调谐部件,故波长切换快、结构简单。西维因农药的荧光特性测量结果表明,系统的荧光波长范围为 500-750nm, 光谱分辨率为 10nm。当激发光波长为320nm,荧光波长为 647nm,西维因溶液浓度为 0.0-120.0μg/L 时,系统具有较好的线性关系,线性相关系数 r 为 0.9991。它可用于对粮食作物中的农药残留的检测和荧光光谱分析。     

红外AOTF调谐关系及其衍射光波长特性研究

对红外AOTF的分光原理和两级衍射光波长特性进行了理论与实验分析.结果表明:AOTF的驱动频率与衍射光波数基本成线性关系;入射角小于57.6°时,两级衍射光波长不等,波长差随驱动频率的增加而减小.分析了影响AOTF分辨率的主要因素,提出了改进方法.     

红外可调声光滤光器的设计和特性分析

根据声光互作用原理，以TeO2晶体为互作用介质，选取互作用长度为28mm，设计制成近红外声光可调滤光器（AOTF），其衍射波长与超声频率存在对应关系。测试结果表明，该器件的工作波长范围为0.9-2.6μm，驱动频率为40－120MHz，光谱分辨力为7.268nm，6.957nm（对应波长分别为1.5μm，2.4μm）。     

声光可调滤光器及其在多光谱成象方面的应用

本文描述了用 TeO_2 晶体制作的大角孔径声光可调滤光器(AOTF)。提出了一种新的晶体取向。对两种晶体取向的调谐关系及分辨率进行了比较。通过改变晶体取向,使AOTF 的性能得到了很大的改善。最后,还讨论了 AOTF 的孔径带宽特性及偏转角,并介绍了 AOTF 在多光谱成象及快速光谱扫描方面的应用情况。     

声光快速分光装置与微机控制

本文介绍了一个以声光可调滤光器为分光元件的快速分光装置,它具有光波长电调谐,易与微机接口,全固态结构等优点。文章详细讨论了快速分光装置各个单元部份电路设计。在Z—80A CPU控制下,分光装置以5nm波长间隙扫描500～700nm光谱范围只需0.74ms。通过模拟实验,快速分光扫描的结果被证明是正确的。     

应用于弹丸跟踪测量的红外器件工作波段选择

目的：探讨利用红外焦平面热像仪对常规快速弹丸目标进行跟踪与测量，以提高对弹丸目标的跟踪测量能力。方法：对靶场试验中常用弹丸目标的光谱辐射特性，背景辐射特性以及大气透过率进行了综合理论分析，并在理论分析的基础上结合试验结果进行分析，结果：对工作波段3um-5um,8um-12um的红外焦平面热像仪以及可见光电视的探测能力进行了比较。结论：响应工作波段为3um-5um的红外热像仪最适于作常规弹丸目标的跟踪测量设备。     

基于AOTF的高光谱偏振成像系统设计

为获得目标和场景的偏振信息,提高目标识别和地物探测的准确度,设计了基于液晶相位可变延迟器(LCVR)和声光可调滤波器(AOTF)的高光谱偏振成像探测系统。首先介绍了偏振成像探测的原理,然后给出了探测系统的结构,并对其光学系统的各元件进行了合理的参数分配,最后利用编制的信息处理软件对系统采集的高光谱偏振图像进行了处理,处理结果能够反映出目标的光谱特性和偏振特性,对于复杂背景下的目标探测与识别具有重要的应用价值。     

全自动红外探测器相对光谱响应测量系统

用付立叶变换红外光谱仪建立了一套全自动红外探测器相对光谱响应测量系统。该系统具有光谱范围宽（１～２５μｍ）、测量速度快、准确度高、操作简便等特点，应用前景广泛。     

Image processing method to improve AOTF spectral resolution and spatial resolution

Abstract

An acousto-optic tunable filter (AOTF) causes the diffracted angle and wavelength to spread, leading to loss of resolution. The light intensity detected by a CCD pixel equals the true intensity plus the stray light caused by the spread of the wavelength and diffraction angle. Here, the true intensity is obtained using neighbourhood estimate recursive correction iteration, improving the spectral and spatial resolution. The spread of acoustic wave angles caused by diffraction is analysed. The reason for the spreads is analysed and derived. A method is reported for measuring the correspondence between the wavelength and diffraction angle spread, using an AOTF, an angle measurement spectrometer and a fibre spectrometer. The iterations’ stop condition is analysed. The improved theory is verified by an AOTF spectral imaging experiment.     

Acousto-optic tunable filter chromatic aberration analysis and reduction with auto-focus system

An acousto-optic tunable filter (AOTF) displays optical band broadening and sidelobes as a result of the coupling between the acoustic wave and optical waves of different wavelengths. These features were analysed by wave-vector phase matching between the optical and acoustic waves. A crossed-line test board was imaged by an AOTF multi-spectral imaging system, showing image blurring in the direction of diffraction and image sharpness in the orthogonal direction produced by the greater bandwidth and sidelobes in the former direction. Applying the secondary-imaging principle and considering the wavelength-dependent refractive index, focal length varies over the broad wavelength range. An automatic focusing method is therefore proposed for use in AOTF multi-spectral imaging systems. A new method for image-sharpness evaluation, based on improved Structure Similarity Index Measurement (SSIM), is also proposed, based on the characteristics of the AOTF imaging system. Compared with the traditional gradient operator, as same as it, the new evaluation function realized the evaluation between different image quality, thus could achieve the automatic focusing for different multispectral images.     

声光技术在测速中的应用

本文描述了一种包含有声光调制器的激光测速系统。着重阐述了原理、实验方法及测试结果,经实验结果和理论分析,这种方法可以用来检测液体、气体、固体的变化速度,而且它和其它激光测速仪相比,频率测量范围宽和测量精度高。     

线阵CCD在颜色测试中的应用

介绍了一种以线阵ＣＣＤ器件为多通道探测器的光源颜色快速测试系统。该系统采用平场凹面光栅为主器件构成多色仪分光系统，测量全过程由微型计算机控制，实现快速，自动的光源能谱及颜色测量。具体给出了系统测试的原理，总体结构，软件和硬件配置，并提供了系统定标方法和实验结果，该系统具有广阔应用前景。     

电站锅炉炉膛温度测量技术发展

该文介绍热电偶测温、CO2红外光谱测温、光纤测温、辐射能测温、声波测温等温度测量方法的原理及其所存在的问题,分析一种基于激光吸收光谱的炉膛测温技术及其系统构成。在某电厂的应用表明,基于激光吸收光谱的测温系统能够对炉膛温度场进行比较精确的测量。测量结果可指导操作人员通过调节相应的二次风门开度等手段来调整锅炉燃烧,使煤粉在炉膛内燃烧均匀,温度场居中分布,从而有效地提高锅炉燃烧效率。     

基于光谱共焦的在线集成表面粗糙度测量方法

为了提高加工检测效率,实现尺寸形位公差与微观轮廓的同平台测量,提出一种基于光谱共焦位移传感器在现场坐标测量平台上集成表面粗糙度测量的方法。搭建实验测量系统且在LabVIEW平台上开发系统的硬件通讯控制模块,并配套了高斯轮廓滤波处理及表面粗糙度的评价环境,建立了非接触的表面粗糙度测量能力。对标准台阶、表面粗糙度标准样块和曲面轮廓样品进行了测量,实验结果表明:该测量系统具有较高的测量精度和重复性,粗糙度参数Ra的测量重复性为0.0026μm,在优化零件检测流程和提高整体检测效率等方面具有一定的应用前景。     

应用超声技术的燃烧气体温度测量方法的研究

高温气体瞬时温度的测量一直是温度测量中的难点，主要原因是温度高，压强大，温度变化速度快。传统的温度测量方法，无法实现温度的快速准确测量。在理想气体中，超声波的传播速度与气体绝对温度的平方根成正比，利用超声波频率差的测量测得气体介质的温度。基于此，本文提出了一种超声温度测量方法并实现了测量系统，同时解决了系统探头的安装、高速计数和数据的二次脉冲锁存问题。     

Acousto-optic tunable filter imaging spectrometer with full Stokes polarimetric capability

Polarization is an important addition to spectral imaging in detecting and identifying objects of interest, and simple linear polarization measurements are often inadequate. Full polarization analysis can give additional information for discrimination where the polarization state is completely described by the Stokes parameters. An acousto-optic tunable filter (AOTF) imaging system was built incorporating two liquid-crystal variable retarders (LCVRs) that can provide complete spectral-polarimetric analysis, and it is believed to be the first demonstration of a full Stokes polarimetric AOTF spectral imaging system with no moving parts. It is also shown that a single LCVR cannot provide all the Stokes parameters.     

Spectral characterization and calibration of AOTF spectrometers and hyper-spectral imaging systems

The goal of this article is to present a novel method for spectral characterization and calibration of spectrometers and hyper-spectral imaging systems based on non-collinear acousto-optical tunable filters. The method characterizes the spectral tuning curve (frequency-wavelength characteristic) of the AOTF (Acousto-Optic Tunable Filter) filter by matching the acquired and modeled spectra of the HgAr calibration lamp, which emits line spectrum that can be well modeled via AOTF transfer function. In this way, not only tuning curve characterization and corresponding spectral calibration but also spectral resolution assessment is performed simultaneously over the whole imaging plane. The obtained results indicated that the proposed method is efficient, accurate and feasible for routine calibration of AOTF spectrometers and hyper-spectral imaging systems and thereby a highly competitive alternative to the existing calibration methods.     

Spectral characterization of integrated acousto-optic tunable filters by means of laser frequency modulation spectroscopy

The spectral characteristics of an integrated acousto-optic tunable filter (AOTF) as well as its responsivity to the rf driving signal and sensitivity to temperature changes are experimentally investigated and quantified using a diode-laser-based interrogation system. A spectroscopic technique, exploiting the rf frequency modulation of the laser beam and the phase-sensitive detection of the AOTF transmission, has been used for this purpose. That allows for the generation of a dispersivelike signal, which serves as a reference for tracking any wavelength change of the filter's peak with high resolution. The possibility of using the integrated AOTF as a spectrum analyzer with this interrogation scheme for fiber Bragg grating (FBG) strain sensing is also discussed.