FT-2100型傅氏光谱仪控制电路及数据采集处理系统

本文阐述了傅氏光谱仪的数据采集及仪器控制电路的设计方法,在自行研制的FT-2100型傅氏光谱仪中,采用了数字PID控制光程扫描电机的转速,分析了影响采样精度的几种因素,还介绍了适用于有关教学的应用软件。     

基于时间相关单光子计数的非接触式荧光层析成像系统

基于时间相关单光子计数(TCSPC)技术原理,研究了一套面向早期乳腺癌检测的时域荧光层析成像系统,系统采用非接触式空间光扫描测量方式,相对于传统的光纤接触式测量方法,可增大空间采样量、减小测量误差、提高空间分辨率.通过仿体实验对系统的成像质量进行了验证,结果表明:单目标仿体实验能较好地对荧光产率与寿命进行重建;在双目标仿体荧光产率的重建中,可有效对中心距为20mm、边距为15mm的目标体进行分辨,且对不同浓度荧光剂目标的重建具有较好的线性.实验结果证明系统应用于乳腺检测的可行性,进一步发展可有望应用于临床乳腺成像中.     

光度测量系统中的光子计数采集卡

光度测量系统需要实时采集并存储光子计数值。针对其高频特点,提出了基于 FPGA 技术和 PCI总线实现高速实时光子计数采集的方法,在 FPGA 内部构造双计数器,很好地实现了无缝计数,从而降低了光子计数的误差。采用 S5933 PCI控制芯片设计的集成采集卡,通用性强,在实用中完全满足高速实时要求。     

基于光子计数调制的光学时域反射测量

针对光学时域反射测量的信噪比受到光子计数的量子起伏的影响,本文提出了光子计数调制技术应用于1.55μm单光子探测光时域反射测量系统,该方法根据相干光场量子涨落的噪声功率在频域上具有均匀分布的特性,采用光子计数调制与锁相放大器解调的方法抑制了量子起伏.实验结果表明,通过改变锁相放大器的积分时间设置滤波带宽,改善了光子计数的信噪比.与光子计数直接测量的结果相比,光子计数调制的光学时域反射测量的信噪改善比达到28.3 dB.     

数据采集系统动态准确的一种评价方法

介绍了一种用于评价数据采集系统动态准确的定义及测度方法，同时评价了其动态条件下的偏置误差、增益误差及模数转换有效位数，最终给出了一种数据采集系统的实际测度评价结果。     

注塑机群实时计数统计系统的设计应用

采用VB编程，通过数据采集和数据录入汇总,达到现场实时计数统计目的。     

一种实时数据采集与监控系统

分布式数据采集和控制系统是一种特别适用于工业现场控制、仪器仪表控制的网络系统。本文主要介绍了基于分布式的仪表的远程数据采集和控制系统；该系统主要包括硬件系统组成结构、软件系统设计和网络的构造，并以实际项目验证了其可行性。     

一种集中分散式数据采集系统的设计

本文设计了一种适用于车辆发动机箱体，汽缸盖等大型零部件应力场实时测量的测试仪。其特点是：整个系统采用集散式结构，由便携式计算机，便携式母系统，微型子系统结构。微型子系统主要完成信号的调理并可直接放在被测体上，测量全过程在计算机和母系统的控制下完成。系统操作简便智能化程度高，具有自动增益自动校准，显示，打印及数据处理等功能；     

线性模拟量数据采集系统准确度的一种评价方法

采用一种新的准确度表述方法来评价数据采集系统的准确度；同时讨论了该方法的数据采集系统各种误差与现有指标的兼容性问题。     

数据采集系统动态准确度的一种评价方法

介绍了一种用于评价数据采集系统动态准确度的定义及测试方法，同时评价了其动态条件下的偏置误差、增益误差及模数转换有效位数，最终给出了一种数据采集系统的实际测试评价结果。     

Data acquisition system for high resolution chopper spectrometer (HRC) at J-PARC

We installed the data acquisition (DAQ) system on the High Resolution Chopper Spectrometer (HRC) at beamline BL12 at the Materials and Life Science Experimental Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC). In inelastic neutron scattering experiments with the HRC, the event data of the detected neutrons are processed in the DAQ system and visualized in the form of the dynamic structure factor. We confirmed that the data analysis process works well by visualizing excitations in single-crystal magnetic systems probed by inelastic neutron scattering.     

Time-correlated single photon counting and optical measurement systems for studying single fluorescent emitters under high vacuum conditions

In this paper, we introduce a modified inverted microscope system in which an objective with high NA (0.95) is located under high-vacuum conditions, and a time-correlated single photon counting system is used along with a modified photomultiplier tube for the characterization of single emitters under high-vacuum conditions. The modified inverted microscope system is designed to be simple, compact, and easy to handle. As an example, the optical properties of individual colloidal semiconductor nanocrystals (CdSe/ZnS) were studied by using these systems.     

宏/子脉冲编码光子计数激光雷达

光子计数激光雷达因其极高的探测灵敏度在远距离目标探测领域有着非常重要的作用。针对远距离、高速度的目标,普通的光子计数激光雷达无法简单通过统计直方图获得有用的回波信息。为了解决这一问题,本文提出了一种基于宏/子脉冲编码的光子计数激光雷达,利用时移脉冲累加的方法提取子脉冲的飞行时间进而在一个宏脉冲内获得目标距离信息。建立了宏/子脉冲编码光子计数激光雷达的理论模型,对虚警概率和探测概率的影响进行了分析,并通过蒙特卡洛仿真和实验验证了其对远距离高速径向运动目标探测的有效性。

     

Time-correlated single photon counting system and light-collection system for studying fluorescence emitters under high-vacuum conditions: Use of immersion objective and ionic liquid

In this paper, we introduce a time-correlated single photon counting system and an efficient light-collection system for studying fluorescence emitters under high-vacuum conditions; the latter system has an immersion objective, and an ionic liquid is used as a refractive index matching medium. The ionic liquid is positioned in high vacuum. The time-correlated single photon counting system has modified photomultiplier tubes that act as photon detectors. The light-collection system is designed to be simple, compact, and easy to use. In order to verify the performance of these systems, the optical properties of colloidal semiconductor nanocrystals (CdSe/ZnS) and fluorescent dye molecules are studied as examples.     

Performance analysis of different pixel-wise processing methods for depth imaging with single photon detection data

We establish a long-range single photon counting three-dimensional (3D) imaging system based on cage optical structure. Five different pixel-wise processing methods for time-of-flight (TOF) photon counting data are compared with data collected by our 3D imaging system for ranges 40–700?m and a suitable representation model for photon counting data is proposed for pixel-wise processing. Experimental results show that these methods exploit the instrumental response function (IRF), yielding a high-quality 3D image. When the signal photon counts are greater than 13 per pixel, the resulting mean absolute error (MAE) values of the IRF-based methods are better than results from the non-IRF-based methods. Regarding IRF-based methods, the union of subspace (UOS) model-based approach and cross correlation are more suitable than the Markov chain Monte Carlo (MCMC) method in the condition of a small number of return signal photons. These results offer valuable information to promote the implementation of photon counting 3D imaging in real applications.     

The statistical properties of continuous wave photon counting based on a multi-pixel photon counter (MPPC)

Second and third order statistics are presented for continuous injected photons counted with a multi-pixel photon counter (MPPC). The number of thermal modes, μ, for the pseudo-thermal light has been acquired under different rotation velocity of the ground glass. At the same time, the MPPC detector's gain coefficient, γ, and cross-talk probability, ε, were achieved through theoretical curve fitting. Finally, we have given an analysis for the saturation effects of the MPPC under continuous injected photons. The results showed that the MPPC model is consistent with the experimental measurement while the photon counting rate was lower than 1200?kcps (threshold), but had larger differences while the photon counting rate was higher than this threshold.     

基于USB2.0的实时数据采集系统研究

本文详细地阐述了基于USB2．0的实时数据采集虚拟仪器系统的设计细节和研究成果。系统采用400MHz增益带宽积的运算放大器，运用DA高精度校准技术，并选用高采样率低噪声的12位AD转换芯片进行模拟电路和AD转换电路设计，保证了数据采集系统的信噪比，提高了系统测量精度。系统还采用预测编码和字典压缩等数据压缩技术，降低了系统数据传输量，并运用USB2．0高速数据串行传输接口技术，实现了数据串行高速传输，满足了高数据吞吐量要求。     

光学计量用高速线阵CCD数据采集系统设计

介绍一种采用高速线阵 CCD 数据采集系统的设计过程。通过一片 MicroChip 公司的在线可编程微控制器对采集系统进行控制,并用标准 RS232 串行接口与外部进行数据通信和控制。在时序逻辑设计中,较好地解决了数据的存储、读取和点像元数据连续监测。实际应用表明该系统能满足光学干涉计量中线阵 CCD 数据采集要求。由于可以对线阵 CCD 进行单点、多点和整块数据的读取处理,因而可适应于不同周期、不同像素数目的线阵 CCD 传感器,以满足多种不同需求。     

A self contained Linux based data acquisition system for 2D detectors with delay line readout

This article describes a fast and self-contained data acquisition system for 2D gas-filled detectors with delay line readout. It allows the realization of time resolved experiments in the millisecond scale. The acquisition system comprises of an industrial PC running Linux, a commercial time-to-digital converter and an in-house developed histogramming PCI card. The PC provides a mass storage for images and a graphical user interface for system monitoring and control. The histogramming card builds images with a maximum count rate of 5 MHz limited by the time-to-digital converter. Histograms are transferred to the PC at 85 MB/s. This card also includes a time frame generator, a calibration channel unit and eight digital outputs for experiment control. The control software was developed for easy integration into a beamline, including scans. The system is fully operational at the Spanish beamline BM16 at the ESRF in France, the neutron beamlines Adam and Eva at the ILL in France, the Max Plank Institute in Stuttgart in Germany, the University of Copenhagen in Denmark and at the future ALBA synchrotron in Spain. Some representative collected images from synchrotron and neutron beamlines are presented.     

Optical asymmetric cryptosystem based on photon counting and phase-truncated Fresnel transforms

We propose a novel optical asymmetric cryptosystem combining the photon counting imaging with phase-truncated Fresnel transform, which can be used for complete information retrieval and authentication verification. The proposed combination overcomes the weakness of photon counting-based double random phase-encoding scheme. For retrieval of original image for authentication, the reverse process of phase truncation approach is followed and a nonlinear correlation filter is used. The complete information retrieval and authentication verification are possible provided sufficient number of photons is available. To check the robustness of the proposed scheme, attack analysis has been carried out. The simulation results are presented to demonstrate the proposed idea.