超高分辨力微型光谱仪的光学系统设计

由于光谱仪的尺寸限制,微型光谱仪在满足一定光谱范围时,其分辨力往往难以小于0.1 nm。而一些特殊应用场合要求光谱仪不仅具有微小的尺寸,还要求具有极高的光谱分辨力。本文基于Zemax光学设计软件,通过选择合适的初始结构参数与评价函数,自动优化准直镜、聚焦镜、柱透镜、光栅,以及CCD间倾角和距离,设计出光谱分辨力高达0.05 nm,尺寸为90 mm×130 mm×40 mm的Czerny-Turner结构微型光谱仪。在此基础上优化出8个光栅倾斜角度,使微型光谱仪光谱分辨力在优于0.05 nm的同时,波段范围达到了820 nm~980 nm。所设计的光谱仪具有超高的光谱分辨力、微小的外形尺寸与适中的光谱范围等特点。     

一种微型光纤光谱仪的研制及其性能测试

报道了一种自行研制的微型光纤光谱仪及其性能测试结果.基于C-T(czerny-turner)成像系统,将通过光纤导入的待测光进行分光后成像于线阵CCD(charge-coupled device)探测器上.采用FPGA(field-pro-grammable gate array)作为主处理器实现CCD的驱动、数据采集与处理,通过USB 2.0接口将数据传送至上位机.根据USB的接口协议及数据格式,编写了一套光谱仪测试软件.利用汞灯作为测试光源,对自制的光纤光谱仪性能进行了仔细分析.结果表明,当采用缝宽为30μm的狭缝时,仪器的波长准确度小于0.3nm,光谱分辨率可达1.1nm.     

静态紫外地球模拟器光学系统设计

静态紫外地球模拟器是一种对紫外导航敏感器进行地面标定和精度测试的设备。本文设计了一种静态紫外地球模拟器光学系统,提出大视场静态紫外地球模拟器光学系统设计方案,对光学系统的参数进行了分析,系统选用七片透镜进行设计,有效孔径为D=10 mm,焦距为f=100 mm,视场角为Φ40°。全视场相对畸变小于0.036%,MTF在50 lp/mm处大于0.7,波像差均方根值小于0.037λ,地球张角偏差??0.006 7°,达到了高精度的指标要求,满足设计要求。     

便携式紫外-可见光谱仪设计及关键技术研究

随着紫外光谱探测技术的广泛应用,低成本便携式紫外-可见光谱仪成为该领域的研究热点。本文首先依据交叉型Czerny-Turner结构设计了便携式紫外光谱仪光路结构。其次,针对性研究了紫外光谱仪的关键器件：紫外探测器和闪耀光栅。利用Lumogen荧光材料和蒸镀成膜法制作镀膜紫外增强CCD,并分析了荧光薄膜在CCD表面的位置对分辨率的影响;从理论上分析了闪耀光栅对于紫外波段的多级衍射效率的影响,确定了紫外光谱仪对于闪耀光栅的选择。最后,研制的便携式紫外-可见光谱仪样机的性能测试结果表明,200 nm~900 nm波段、25 μm狭缝宽度、600 lp/mm、300 nm闪耀光栅配置下分辨率整体小于1.5 nm,200 nm~300 nm紫外波段的光谱响应度提高到20%,实现了便携式紫外-可见光谱仪的设计要求。     

一种紫外光谱测量的微型光纤光栅光谱仪设计

介绍了用于太阳紫外光谱250nm～450nm测量微型光纤光栅光谱仪,该谱仪采用C-T正交型结构,采用滨松自扫描光电二极管阵列(SSPD)为探测元件,介绍了谱仪的辐射定标和探测器驱动及数据采集电路设计,讨论了积分时间与信噪比之间的关系。     

基于散斑检测的微型计算光谱仪研究进展

光谱分析技术具有快速、准确和绿色检测的特点,在科学研究、信息、生物医疗、食药检测、农业、环境和安防等领域有广泛而且重要的应用.然而现有光谱技术与检测设备通常较为庞大复杂,难以适合现场快检、轻载荷平台等便携式应用场景.近年来,微型光谱检测技术和设备受到广泛关注并得到迅速发展,具有尺寸、重量、功耗等方面的显著优势,尤其是基...     

高斯光束均束器光学系统设计

为了提高激光光束的应用水平,需要将高斯光束整形为平顶光束。分析了非球面高斯光束均束器的基本原理和设计理论,选用超高斯光束函数作为平顶光束的数学-物理模型,建立了入射高斯光束与出射平顶光束之间的映射关系式,给出了高阶非球面的面型参数,利用光学设计软件ZEMAX设计了高斯光束均束器光学系统。系统入射光束直径为2 mm,出射光束直径为4 mm,激光波长为1064 nm。分析了能量转换效率,根据Bessel公式定义了平顶光束的平顶度。设计结果实现了激光束的2倍准直扩束、95.98%的能量转换效率和96.6%的平顶度。     

基于光纤光谱仪的微型分光光度计

结合光纤光源、50μL微量比色皿、微型光纤光谱仪,设计一款可用于微量样品吸光度测定的微型分光光度计。并用邻二氮菲测铁的经典分光光度分析方法,将该微型光度计与传统紫外可见分光光度计进行比较,结果表明该微型分光光度计的精密度、灵敏度、线性范围和线性相关性等性能均与传统紫外可见分光光度计一致。最后通过国家一级标准物质测试结果,验证该微量光度计能满足实际样品的准确测定。     

一种交叉的切尔尼—特纳型远紫外成像光谱仪

本文介绍了远紫外成像光谱仪的需求和若干关键技术,描述了一种光谱范围为100～300nm,光谱分辨率优于1.67mm的远紫外波段成像光谱仪的设计方法和定标实验.该仪器基于交叉的切尔尼-特纳型光谱仪光路结构,采用全反射式系统.根据初级像差理论设计了光学系统,使用Zemax进行了仿真和优化,在紫外-可见光波段对仪器的性能进行实验验证,并进行了光谱定标和成像性能分析.     

基于MATLAB的光纤光谱仪校准的测试方法

采用光谱辐照度标准灯进行量值传递和MATLAB数据处理技术等来实现对光纤光谱仪的计量。简述了这种计量方法的工作原理以及数据处理过程。从理论分析和初步的实验结果证明了这一方法的有效性和可行性。     

Analysis of a high-speed fiber-optic spectrometer for fiber-optic sensor signal processing

A novel high-speed fiber-optic spectrometer has been demonstrated in our previous work. The high-speed spectrum measurement is enabled by translating the spectral-domain signal into a time-domain signal through a dispersion element. We present a mathematical model that accurately describes the relationship between the optical spectrum to be measured and the dispersed time-domain signal. Based on the model, the effects of the key parameters on the performance of the spectrometer are investigated in detail using numerical simulation. The analysis is useful for the design and application of such spectrometers.     

Some characteristics of a miniature neutron spectrometer

Some characteristics of an NE213 miniature spherical spectrometer for in-assembly fast-neutron spectrometry were measured. As the bubbling time changed, the pulse-height did not change appreciably, but the n?γ discrimination characteristics changed considerably. As the count rate changed, the pulse-height did not change appreciably, and the change of the n?γ discrimination characteristics was acceptable. The neutron response function was measured to be almost isotropic except for the backward direction.     

Diffusion-engineered single-photon spectrometer for UV/visible detection

We present predictions for a diffusion-engineered, single-photon spectrometer in the UV–visible range using a superconducting tunnel junction. Quasiparticles are created by photoexcitation, with charge Q₀. After tunneling through the junction, the quasiparticles can either backtunnel or diffuse away. With confinement by a higher gap or by narrow leads the quasiparticles in the counterelectrode dwell next to the junction and backtunnel, increasing the collected charge to Q=pQ₀, p>1. For very narrow leads the dwell time is inversely proportional to the lead width, up to the recombination time of Al, 1 ms at 0.2 K. The new aspect of our work is the use of narrow leads to control the charge gain p, while minimizing self-heating. This charge gain will improve the energy resolution compared to the case p=1, where the electronic noise is dominant, and compared to much larger charge gain, p≈50, where large self-heating resulted with extra noise.     

Development of a miniature magnetic sector mass spectrometer

A miniaturized magnetic sector mass spectrometer has been developed and tested. The instrument was designed the number two filament in ion source, in order to avoid failure of the number one filament. It has a 90° magnetic sector-field analyzer with double trajectory, which has a magnetic flux density of 0.65 T. Two special trajectories are selected to cover the mass ranges, 1-12 amu and 6-50 amu. The mass spectrometer’s overall size, including the magnet assembly, is 250 mm wide, 250 mm long and 160 mm tall, it weighs 2.5 kg, and its power consumption was measured to be 15 W. It was able to attain a mass resolution of 56 at full-width at half-maximum and a sensitivity of 7.7 × 10⁻⁵ A/Pa. The resulting design is small, lightweight, and has low power consumption. All these characteristics make this miniature mass spectrometer suitable for space applications and chemical analysis and also for field applications on earth.     

Atmospheric pressure ionization in a miniature mass spectrometer

A miniature cylindrical ion trap mass spectrometer featuring an atmospheric pressure interface allowing atmospheric pressure chemical ionization and electrospray ionization is described together with its analytical performance characteristics. The vacuum system, ion optics, mass analyzer, control electronics system, and detection system have all been designed and built in-house. The design is based upon a three-stage, differentially pumped vacuum system with the instrument capable of being interfaced to many types of atmospheric pressure ionization sources. Ions are transferred through home-built ion optics, and instrument control is achieved through custom-designed electronics and LabView control software. Corona discharge ionization and electrospray ionization sources are implemented and used to allow the analysis of both gaseous- and solution-phase samples during the characterization of the instrument. An upper mass/charge limit of approximately 450 Th with unit resolution was achieved using a 2.5-mm-internal radius cylindrical ion trap as the mass analyzer. The specificity of the instrument can be increased by employing the MS/MS capabilities of the ion trap and has been demonstrated for nitrobenzene. Limits of detection for the trace analysis in air of the chemical warfare agent simulant methyl salicylate (1.24 ppb) and for nitrobenzene (629 pptr) are achieved. The dynamic range of the instrument is currently limited to approximately 2 orders of magnitude by saturation of the detection electronics. Isolation and collision-induced dissociation efficiencies in MS/MS experiments both greater than 50% are reported. Electrospray/nanospray data are presented on solutions including 100 microM (D,L)-arginine, 10 microM (-)-ephedrine, and 10 microM lomefloxacin.     

The monitoring system of a high performance fusion neutron spectrometer

Neutron emission spectroscopy (NES) diagnosis of high-power fusion plasma has been performed with the magnetic proton recoil (MPR) spectrometer installed at the Joint European Torus tokamak. The MPR is a high performance instrument where the setting of working points to prescribed calibration values is essential. This includes the MPR focal plane detector whose photomultipliers must be monitored for gain stability with respect to short- and long-term drifts as well as transient changes. A special monitoring system was developed for the MPR including a light pulser in the form of light emitting diodes. The monitoring system as part of the MPR focal plane detector is described here as well as the monitoring procedures and applications. Results from the use of the monitoring system are presented illustrating its present capabilities and possibilities for further developments in next step NES diagnostics.     

高频微型热声制冷机的样机设计与性能预测

介绍了高频微型热声制冷机的设计和性能分析,确定和部分优化了5 kHz压电喇叭驱动的热声实验样机的设计参数,为探索接近超声波频率的微型机工作的可能性,同时也对15 kHz微型热声制冷器进行了性能预测,并给出了主要参数,为高频微型热声制冷系统的实验研究提供了样机设计和性能预测.     

Pressurized line pipe wall thinning detection using a distributed fiber-optic sensing system

Wall thinning defects in steel pipes are usually localized and are difficult to detect using traditional sensors that have a small coverage and limited measuring range. A distributed fiber sensor, based on the Brillouin backscattering sensing system, has been demonstrated to be able to measure the strain and detect the defect in a pipe accurately. A 1.8 m pipe segment that contains artificial thinning from 13 to 60% of wall thickness at various positions was subjected to an internal pressure of 350 kgf/cm². Hoop strain distribution along the whole pipe segment was monitored by a single optical fiber. The measured strains compared favorably with strain gauge results. The method proposed in this study shows promising results for the detection of the existence and location of wall thinning defects in long distance pressurized pipe.