Two-color optical charge-coupled-device-based pyrometer using a two-peak filter

A two-color optical charge-coupled-device (CCD)-based pyrometer was developed using a multipeak interference filter with a color CCD sensor to measure multicolor signals with specified wavelengths. The effective and simple method adjusts the fixed spectrum response characteristics of a color CCD to allow improved temperature measurements. This pyrometer system not only has the advantage of traditional two-color (two-wavelength) pyrometry, but also overcomes the restrictions of color CCDs that can only be applied in waveband measurements. The measurement performance of the system using a two-peak filter (λ(1)=643?nm,?λ(2)=564?nm) was evaluated by blackbody experiments. The results show that the low temperature detection limit is increased about 200 K with an increase in the sensitivity of the measured signals compared with the original system without two-peak filter [Fu, et al., Opt. Laser Technol. 42, 586 (2010)]. And the effective temperature range is also increased when T > 1233 K. The measured ratio C(R)/C(G) is monotonically relative to the temperature, which simplifies the measurements. The temperature sensitivity of 2.49 is larger and more uniform than the temperature sensitivity of 1.36 in the previous original system. Thus, the measurement performance of the new system is greatly improved. Finally, as an application, the surface temperature distribution of stainless steel sample in hot environments was determined by this new CCD-based pyrometer. The results agree well with the spectrometer-based results and further verify the applicability of the new system.     

窄带辐射高温计新的标定方法

本文介绍了一种基于波长函数ＰＷＦ的标定方法,由于该法以光学标定简化窄带辐射高温计的温度分度,故障低辐射高温计的标定成本,标定精度高,可用于标准器的标定,因而有广泛的应用前景。     

基于线阵CCD的光谱仪定标研究

光谱仪是一种基本光谱检测和分析仪器,以线阵CCD为探测核心是设备微型化的重要手段,CCD各光敏像元输出信号与待测光谱波长及光谱辐射通量之间对应关系成为定标的主要内容.研究了常规线性拟合方法,应用校准结果测量发现有时误差较大,利用低压汞灯特征谱线为基准,采用最小二乘法曲线拟合完成波长定标,计算出拟合曲线的3阶校正参数;利用辐射标准灯完成光谱辐射定标,解决了光束经过光学系统传输损耗及线阵CCD光谱响应灵敏度测量的困难,并对定标方案进行了数学推导证明.对大量实验数据进行分析表明,该定标方法是切实可行的,并成功应用到微型光谱仪器的生产过程.     

基于波长积分双色法的小视场快速温度场测量

激光退火技术有热预算低、瞬间温度高的特点,其温度场特性是材料电学性能的重要表征参数.准确实时测量瞬态小温度场对整体退火工艺过程的把控具有重要的参考价值.辐射测温法通过收集样品辐射光谱中特定波段的能量来实现温度的非接触在线测量,具有响应快、测温范围宽等特点.提出了一种基于InGaAs红外光电二极管的双色辐射测温系统设计方...     

A universal pyrometer for molecular-beam epitaxy setups

A universal fiber-optic pyrometer for the molecular-beam-epitaxy growth module developed in collaboration with JSC Semiconductor Technologies and Equipment is described. This instrument is designed for controlling the technological process of growing semiconductor heterostructures on substrates of various types (GaAs, InP, Si, and sapphire). The pyrometer allows measurements of the temperature of semiconductor substrates to be performed in the range 450–1200°C with an accuracy no worse than ±0.5% under the conditions when such characteristics as the emissivity of the material, the transparency of the optical medium, and the dimensions of the studied surface are unknown. These feasibilities can be realized owing to the use of a procedure of periodic calibration of the pyrometer against an actual object directly during the technological cycle with the use of additional information on the object temperature.     

分析超速离心机的多波长检测系统及其应用

分析超迷离心技术应用离心力场在对样品分级分离的同时借助光学系统检测离心池内大分子分布及相互作用。本文阐述用于分析超迷离心机的新型多波长检测器（MWL-AUC）,它以现代CCD uv-vis分光仪为基础,几乎可用所有波长的光线同时检测同一半径处沉降样品的分布,通过沉降平衡和沉降速度试验能够获得更多信息源并应用于生物科学和工业多聚物的研究。     

基于彩色CCD的高温场辐射测温方法

针对基于彩色CCD的高温场辐射测温问题,提出利用红、绿基色值进行比色测温来获取单一光圈快门组合内的最大测温范围,并进一步利用变换光圈快门组合来使得测温范围能够覆盖高温生产的常用温度范围;通过标定减少CCD光谱响应带宽和被测对象光谱发射率对测温精度的影响,提高测温精度.在此基础上,开发了CCD高温场测量仪.计量校准结果表明,测温仪具有较高的测温精度和实用性,能够满足常见高温生产过程对于温度测量的应用要求.     

Time resolved temperature measurements in manufacturing

Fast surface temperature measurements are of high interest in manufacturing processes. They can be realised by radiation techniques. Main problems are various influences on the accuracy and the limited optical access of interesting measurement positions. Therefore a fast fibre-optic two-colour pyrometer with high local resolution has been developed which enables measurements of surfaces with unknown emissivities. This pyrometer has been applied in a turning process, where the fibre-optic enables different measurement positions to show the influences of cutting speed and tool wear on the temperatures.     

可调谐激光器激光波长宽范围自动偏频锁定

针对激光多波长干涉绝对测距中构建多级合成波长的需求,提出了一种锁至飞秒光频梳的可调谐激光器(External CavityDiode Laser,ECDL)输出激光波长的宽范围自动偏频锁定方法。首先,设计了光栅+双凸透镜梳齿滤波的拍频信号探测单元,实现了宽范围ECDL激光波长与目标梳齿的拍频探测。接着,采用锁相放大原理对拍频信号进行鉴频鉴相,具备捕获带宽大、鉴相范围宽和鉴相精度高的优点。然后,利用多重闭环控制实现了ECDL输出激光波长宽范围的自动调节及偏频锁定。实验结果表明,本方法实现了10 nm波长范围内ECDL至光频梳的自动锁定,拍频信号信噪比的平均值约为35.9 dB;在4h内,ECDL激光频率的标准差为1.49 kHz,1s平均时间的相对阿伦方差为4.76×10^-12,满足精密干涉测量中宽范围波长调节和高精度稳频的要求。     

光纤色散法测量闪烁体脉冲光谱

提出了一种利用光纤波长色散测量脉冲光谱的方法.由于具有较宽光谱的脉冲光在一定长度的光纤中传播时会发生波形展宽,需要根据测量和标定结果校正展宽的波形才能得到光源的实际光谱曲线.标定时首先利用ps级脉冲光源对测量系统进行时间响应标定,得到系统的时间响应函数;接着测量不同波长光的走时,得到不同波长的群折射率;最后测量光纤中的光谱衰减,得到各种波长的相对衰减或传输效率.利用以上3个标定结果,对波形进行数字逆卷积,并进行走时校正和衰减系数校正,即可对所得到的波形进行恢复.经实验测量和数据处理,得到了一种红光闪烁体的发光光谱曲线,其中心波长与用其他方法测到的中心波长的差小于2 nm,谱线形状基本一致.研究显示,在脉冲光的脉冲宽度远小于其色散展宽时,可以利用光纤的波长色散对脉冲光的光谱进行测量.     

椭圆型晶体谱仪谱测量的解谱

描述了椭圆型晶体谱仪配X射线CCD相机的X射线谱测量系统(EBCS-XCCD),研究了CCD相机记录信号的解谱处理方法,推出了对实测原始谱曲线辨认或标识值的计算公式及激光等离子体辐射X射线在某一波长光谱强度的公式,使之应用在激光打靶产生的等离子体源辐射X射线谱的回推,辨认出了激光等离子体X射线源能谱,并与文献[1]的结果进行了比较,结果基本一致.测试结果证实了解谱方法的可行性,表明X射线CCD相机适用于椭圆型晶体谱仪的光谱测量记录.在已知晶体的积分反射率、滤片透射率和CCD探测效率的条件下,可以获得X射线源光谱强度,为下一步诊断激光等离子体的电子温度和离子密度的空间分布轮廓和进一步细化X射线激光研究奠定了基础.     

铸坯表面温度场测量仪的研究

基于面阵CCD(charge coupled device)的测温系统可以有效克服氧化皮对铸坯表面温度测量的干扰,近年来成为高温测量领域研究的热点。但CCD的非线性关系导致动态测温范围窄、低温段测量精度低。基于窄带带通滤光片建立了单光谱辐射CCD测温模型,据此研制了由滤光片、CCD、CCD信号处理器及DSP构成的铸坯表面温度场测量仪。通过一点标定和自适应调整光积分时间,扩展了CCD测温范围,同时改善了低温段的测量精度,使各温度段测量结果趋于等精度分布;采用4级流水线机制及DSP、工控机(industrial personal computer,IPC)2级数据处理结构,提高了系统的实时性;该仪器还具有暗电流补偿和以太网传输功能。通过黑体炉标定和现场测量,结果表明研制的测温仪满足铸坯表面温度场测量要求。     

A dual-band adaptor for infrared imaging

A novel imaging adaptor providing the capability to extend a standard single-band infrared (IR) camera into a two-color or dual-band device has been developed for application to high-speed IR thermography on the National Spherical Tokamak Experiment (NSTX). Temperature measurement with two-band infrared imaging has the advantage of being mostly independent of surface emissivity, which may vary significantly in the liquid lithium divertor installed on NSTX as compared to that of an all-carbon first wall. In order to take advantage of the high-speed capability of the existing IR camera at NSTX (1.6-6.2 kHz frame rate), a commercial visible-range optical splitter was extensively modified to operate in the medium wavelength and long wavelength IR. This two-band IR adapter utilizes a dichroic beamsplitter, which reflects 4-6 μm wavelengths and transmits 7-10 μm wavelength radiation, each with >95% efficiency and projects each IR channel image side-by-side on the camera's detector. Cutoff filters are used in each IR channel, and ZnSe imaging optics and mirrors optimized for broadband IR use are incorporated into the design. In-situ and ex-situ temperature calibration and preliminary data of the NSTX divertor during plasma discharges are presented, with contrasting results for dual-band vs. single-band IR operation.     

Characterisation and laboratory investigation of a new ultraviolet multi-wavelength measuring system for high-temperature applications

In the framework of the HiTeMS project of the European Metrology Research Pogramme (EMRP) a new multi-wavelength device for measurement of high temperatures in industrial applications was developed at INRIM. The apparatus takes advantage of the ultra-violet operation with working wavelengths from 350 nm up, which reduces the possible errors connected with the multi-wavelength approach. The instrument has been characterised in terms of optical and electronic behaviour and some laboratory trials were carried out to verify the reliability of the multi-wavelength approach. The true temperature of a blackbody source at 1300 °C with optical windows of unknown spectral transmittance interposed has been defined. By applying an approach that allows a result to be accepted when a threshold limit is reached, it was found that, when an acceptable result can be obtained, errors are comprised within less than 1% of the temperature of the source. Three others single-band thermometers, at 508 nm, 650 nm and an IR broadband 0.8–1.1 μm, were also used to the purpose of a comparison. It has been found that, when the multi-wavelength approach is applicable, it provides generally better or in few cases, at worst similar results of corrected single-wavelength thermometers.     

一种改进型非交叉非对称 C-T 结构近红外 微型光谱仪设计

针对基于固定光栅和阵列探测器的常规微型近红外光谱仪成本高、光谱范围窄等问题,提出了一种基于集成扫描光栅微镜的双探测器微型近红外光谱仪。该系统采用自制的集成扫描光栅微镜作为核心分光部件,可同时实现扫描与分光功能,光学系统设计利用两个聚焦镜和两个InGaAs单管探测器的空间布局避免不同光路之间的相互干扰,可实现双通道同时、独立工作,此外双通道探测器前内置不同截止波长的带通滤色片消除光谱重叠。采用光线追迹法建立了理论模型计算光学系统的初始结构参数;利用ZEMAX完成了光学系统的优化设计并给出优化结构参数。测试结果表明,该仪器工作波长范围:800～2 532 nm,分辨率:小于12 nm(800～1 600 nm)、小于17 nm(1 600～2 532 nm),整体尺寸:145 mm×135 mm×75 mm,具有宽光谱、小体积、低成本等优势。     

多波长激发高分辨率微型拉曼光谱仪设计

针对不同激光波长激发测试样品所需拉曼光谱范围的差异性问题,同时为了保证拉曼光谱仪的小型化及高分辨率需求,提出一种以Czerny-Turner光路结构为基础的微型拉曼光谱仪,通过Zemax光学设计软件对光谱仪的准直镜、聚焦镜、柱面镜、光栅以及CCD的倾角及距离进行了优化。该仪器激光波长为633 nm,光谱范围为640～800 nm。进一步优化光栅旋转角度并配合聚焦镜,可使此光学系统同时适用于激光波长532 nm、光谱范围540～650 nm和激光波长785 nm、光谱范围790～1 000 nm两个波段。拉曼光谱仪分辨率为0.1 nm,该光谱仪在保证高分辨率的情况下解决了不同波段范围光学结构差异性大而导致光机设计很难整合在一起的问题。     

High accuracy wavelength calibration for a scanning visible spectrometer

Spectroscopic applications for plasma velocity measurements often require wavelength accuracies ≤0.2?A?. An automated calibration, which is stable over time and environmental conditions without the need to recalibrate after each grating movement, was developed for a scanning spectrometer to achieve high wavelength accuracy over the visible spectrum. This method fits all relevant spectrometer parameters using multiple calibration spectra. With a stepping-motor controlled sine drive, an accuracy of ～0.25?A? has been demonstrated. With the addition of a high resolution (0.075?arc sec) optical encoder on the grating stage, greater precision (～0.005?A?) is possible, allowing absolute velocity measurements within ～0.3?km/s. This level of precision requires monitoring of atmospheric temperature and pressure and of grating bulk temperature to correct for changes in the refractive index of air and the groove density, respectively.     

辐射光纤高温计及其系统的研究

为解决特殊情况下的高温在线测量，研制了一种辐射光纤高温计。介绍了仪表的工作原理、光滤波及测试结果的处理。     

纳米级微间距的多波长干涉测量方法

多波长干涉测量法适用于纳米级微间距的实时动态非接触测量.纳米级间隙之间的空气形成一层具有光学特性的空气薄膜.该空气薄膜的光强反射率是关于入射光波长和薄膜厚度的函数.在多波长干涉法中,以包含多种波长的复合入射光照射薄膜,入射光被空气薄膜分成2部分,一部分穿过薄膜,另一部分则被反射回来.利用一种特殊的方法测得该薄膜的光强反射率,进而根据薄膜厚度与入射光波长和相应的光强反射率之间的函数关系建立方程组.通过对方程组求解,计算出薄膜的厚度.多波长干涉测量法能够避免移相干涉法中移相器所带来的误差,并且可根据不同波长的光波测出的结果相互校正,提高了测量精度.通过实验对多波长干涉测量法进行了验证,实验结果充分证明了系统设计及理论依据的正确性.