Data Acquisition And Processing System For Single Photon Detection

Computer-aided system of signal sampling and data processing is a product of the high technologies, including high performance integrated circuits technique, computer bus and virtual instrument, which is widely used in the fields of industry and scientific research. Data acquisition and processing system, which is based on PCI high speed multifunction data acquisition card, is important for quantum information processing, not only the detected signal of photons can be displayed conveniently in real time, but also the post flexible data processing can be achieved.In this paper, the basic features of the single photon detector (SPD) composed of InGaAs avalanche photodiode (APD), including the structure, specifications and working mode, are briefly introduced in the beginning. Then, based on the principle of data acquisition, PCI bus technique, as well as the performance and working mode of NI high-speed M series multifunction DAQ PCI-6251, a data acquisition system has been built for high-speed single photon detection. The main achievement of the paper is the development of a application program for the data acquisition of SPDs in both single and double channel by using LabVIEW8.20 which is based on graphics language. With the developed data acquisition system, the detected signal can be analyzed, processed and stored. To test its performance, it has been used to process the data of correlated photon pairs generated in optical fiber. The experimental results show the system well satisfies with the requirements of the data processing, which can display the detected signal in real time and store the related data for further processing. However, the data acquisition and analysis can't be placed in the same loop at a higher-speed data acquisition due to the executable process of the data stream. To solve the problem, the Producer-Consumer pattern is proposed to improve and to optimize the performance of the developed system.