Development Of A High-Speed Intelligent Photon Coincidence Instrument

Quantum information science is another milestone of development of Information science. It is a rising interdisciplinary field that combines quantum mechanics and information science. Now,electronics and computer is still very important supplementary means for studying fields of quantum information science. It is implemented by electronics for information sampling, processing, controlling and presentation on quantum communication and information processing. So,we develop the photon coincidence instrument using by modern circuit and computer,it is very important measure instrument in common use for quantum communication and information processing.In addition, polarizer is a necessary elementary optics device In quantum communication, which can control the directions of photon polarization (or transmission) for both sides. So it is very important to precisesly control the localization of polarizer.After many researches and analyses on physics sense and principle of photo coincidence instrument,we present a design scheme for high-speed intelligent photon coincidence instrument.Based on studying the key technology of the scheme,we crystallize and implement the scheme with moderm IC and computer.The photon coincidence instrument capture and sample the narrow pulse from single photon detector by using high-speed ECL(emitter coupled logic),and then send the data to high-speed buffer. FPGA preprocesss the raw data of high-speed buffer,and send it to computer through usb 2.0 high-speed interface for real-time measuring, reprocessing,analyzing and storing.We describe the design and implement of hardware for the photon coincidence instrument,present the control flow and design of software.Otherwise,we develop the autocontrol system for controlling the polarizer, which can be precisely rotated in different directions and angles by application software.The photon coincidence instrument has the features of high-speed, multi-channel, real-time measuring and narrow coincidence window.The experiment results proved that the hardware and software of the photon coincidence are up to the design requirements. Finally,the photon coincidence instrument can be cooperated with the autocontrol system for polarizer,which can precisely control the direction of photon in the optics circuit.,and it can be established as a unattended and intelligent measure system.