多通道光子到达时间测量中高精度时间数字转换器的研究  

High-Resolution Time-to-Digital Converter for Multichannel Photon-Arrival-Time Measurements

作　　者：葛文博 郭龑强 林发定[1] 崔馨璇 郭晓敏 Ge Wenbo;Guo Yanqiang;Lin Fading;Cui Xinxuan;Guo Xiaomin(Key Laboratory of Advanced Transducers and Intelligent Control System,Ministry of Education,Shanxi Province,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China;College of Physics,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China)

机构地区：[1]太原理工大学新型传感器与智能控制教育部重点实验室,山西太原030024 [2]太原理工大学物理学院,山西太原030024

出　　处：《中国激光》2025年第2期111-121,共11页Chinese Journal of Lasers

基　　金：国家自然科学基金(62075154,62175176,U23A20380);国家重点研发计划(2022YFA1404201)。

摘　　要：在光场高阶光子关联测量中,需要利用高精度时间数字转换器(TDC)实现对光子到达时间的精确测量,并且时间数字转换器对光子到达时间测量的精度起着决定性作用。本课题组利用现场可编程门阵列(FPGA)硬件平台研发了一种精确测量光子到达时间的8通道高精度时间数字转换器采集系统。结合“粗计数”与“细测量”实现高精度测量,并发展了CARRY4两抽头(CO0和CO3)结构以构造抽头延迟链,从而实现细测量,在克服超前进位限制的同时有效提升了时间数字转换器的分辨率。通过使用切换输入级和双模式单计数器编码,将时间数字转换器的死区时间减少到一个系统时钟周期。采用码密度校准法对延迟单元的非线性时延进行校准,并通过千兆以太网进行数据传输。实验结果表明:研发的8通道高精度时间数字转换器的平均分辨率为34.7 ps,精度为26.3 ps;对于1模式,微分非线性范围为(-0.75t_(LSB),1.5t_(LSB)),其中t_(LSB)为系统的时间分辨率,积分非线性范围为(-2t_(LSB),2.8t_(LSB));对于0模式,微分非线性范围为(-0.76t_(LSB),1.32t_(LSB)),积分非线性范围为(-1.2t_(LSB),1.9t_(LSB))。最后,在时间相关单光子计数测量系统中对该时间数字转换器件进行验证,证明了该系统在多通道光子到达时间测量方面的可行性。Objective In the measurement of high-order photon correlation in light fields,high-precision time-to-digital converters(TDCs)are required to accurately measure the photon arrival time.The purpose of this study is to develop a multichannel high-precision TDC acquisition system that can accurately measure the photon arrival time using a field-programmable gate array(FPGA)hardware platform to support the high-order coherence of the light field,which can be accurately obtained via high-order photon correlation measurements of the light field.Methods In this study,a multichannel photon-arrival-time measurement design was implemented using XC7A100TFGG484 of the Artix-7 series.By combining“coarse counting”and“fine measurement”and developing the CARRY4 two-tap(CO0,CO3)structure,we constructed a tap delay chain for fine measurement,which improves the resolution of the TDC while overcoming the limitations of overfeeding.The dead time of the TDC was reduced to one system clock cycle using a switching input stage and dual-mode singlecounter coding.The nonlinear delay of the delay cell was calibrated using the code-density calibration method,and the data were transmitted over gigabit ethernet.Subsequently,a test platform was constructed to continue implementing testing and data analysis for the TDC.Finally,the TDC device was verified using a time-correlated single-photon counting measurement system.Results and Discussions Accuracy was tested using a signal generator to generate a set of fixed time intervals from small to large to obtain the variation in the accuracy with the time interval.The maximum and minimum accuracies are approximately 25.6 and 20.1 ps,respectively(Fig.10).The accuracy of the system was tested and counted for each of the eight channels,and the accuracy of the system was obtained as 26.3 ps(Fig.11).The accuracy at different temperatures was measured at a time interval of 90.91 ns,and the variation in the accuracy error over the temperature range was 2.6 ps(Fig.12).The results clearly indicate the

关 键 词：时间数字转换器 光子到达时间 现场可编程门阵列 抽头延迟链 码密度测试 

分 类 号：TH714[机械工程—测试计量技术及仪器]