Photon-number-resolving Detection And Its Quantum Detector Tomography

Photon-number-resolving detection(PNR)at the single-photon level is at the frontier of the research of quantum optics,and it is one of the key techniques in the research of quantum state preparation and quantum processes.Especially,in quantum information,the PNR detection is the basis in some protocols of quantum repeaters and linear optics quantum computing.At present,there are several schemes to realize PNR detection.Among them,InGaAs/InP avalanche photodiode(APD)worked in gated Geiger mode is the most popular devices used to detect single photon in the near-infrared communication band.Normally,as the spike noise is generated by the gate pulse applied on the APD,it is quite difficult to capture the original avalanche signal,which disables the capability of PNR detection except temporal or spatial multi-plexing.But if the spike noise is very well suppressed so that the APD could be operated in the sub-saturation mode.Hence PNR could be achieved with a single APD.In addition,in order to describe the PNR detection in a quantum way,the full quantum characterization of the PNR detection is of great importance in addition to the traditional parameters such as detection efficiency,dark count and afterpulse.The quantum detector tomography was first proposed by J.S.Lundeen et al.in Nature Physics in 2009.The corresponding positive operator-valued measure(POVM)of the PNR detector can be deduced from QDT,which becomes the standard for the quantum characterization of the PNR detector.By QDT,we can evaluate whether the PNR detector can be applied in a real quantum optics system.This thesis is mainly focused on the research of the PNR detection based on InGaAs/InP APD.The self-balanced spike signal cancellation technique was applied to capture the avalanche in less distortion.By analyzing the distribution of the peak amplitude of the avalanche signal,the InGaAs/InP-APD-based PNR detection is realized in a direct way.Then,the double-balanced spike signal cancellation technique was raised to improve the signal-to-noise ratio of the avalanche signal,while further compressing the spike signal,which improves the performance of the PNR detection.In this thesis,a high-speed time-multiplexing infrared PNR detector using a self-developed multi-channel 200 MHz single-photon detector based on InGaAs/InP APDs is demonstrated.And the quantum detector tomography to reconstruct the associated positive operator-value measures is deduced.In order to verify the accuracy of the reconstructed POVM,the result calculated from the reconstructed POVM was compared with the result in the experiment and theoretical simulation,which shows a perfect agreement.The appearance of the negative values of the Wigner function corresponding to the reconstructed POVM indicates the absence of a classical optical analogue.Therefore,the PNR detector is a fundamental quantum detector.The innovations in this paper:1.The PNR detection based on InGaAs/InP APD was realized by using the self-balanced spike signal cancellation technique.The double-balanced spike signal cancellation technique was proposed and demonstrated.The signal-to-noise ratio of the avalanche signal was increased by 11.2 dB.2.A multi-channel 200 MHz single-photon detector based on InGaAs/InP APDs was developed.The detection efficiency of each channel was up to 25%.The dark count of each channel was below/Pulse,while the detection efficiency was 10%.3.A time-multiplexing PNR detector was devised with the multi-channel single photon detector.And the corresponding POVM was experimentally reconstructed by the QDT,The fidelity of the distribution of the detector’s output represented from the reconstructed POVM is 99.99%.