Quantum detector tomography of a single-photon frequency upconversion detection system

Abstract

We experimentally presented a full quantum detector tomography of a synchronously pumped infrared single-photon frequency upconversion detector. A maximum detection efficiency of 37.6% was achieved at the telecom wavelength of 1558 nm with a background noise about 1.0 × 10^-3 counts/pulse. The corresponding internal quantum conversion efficiency reached as high as 84.4%. The detector was then systematically characterized at different pump powers to investigate the quantum decoherence behavior. Here the reconstructed positive operator valued measure elements were equivalently illustrated with the Wigner function formalism, where the quantum feature of the detector is manifested by the presence of negative values of the Wigner function. In our experiment, pronounced negativities were attained due to the high detection efficiency and low background noise, explicitly showing the quantum feature of the detector. Such quantum detector could be useful in optical quantum state engineering, quantum information processing and communication.

How to Project onto an Arbitrary Single-Photon Wavepacket

“…Here, the capacity to adjust the width of the spectral mode Ψ(ω) provides Alice and Bob a new strategy to mitigate Eve's attack and extract a secure key. More generally, detector tomography is an important tool across implementations of single-photon and number-resolved photo detection [7,8,83,84]. Realtime tomography could be useful in QKD protocols resistant to "trojan-horse attacks" [85] or any SPD platform subject to time-dependent environmental parameter fluctuations: for instance, atmospheric turbulence in MDI-QKD [86] or interplanetary medium in deep space classical communications [87].…”

Metrology Perspective of Single‐Photon Detectors: Review on Global Calibration Methods

“…Moving ahead from a single photon, even the calibration setup for multiphotons has begun to emerge. [ 70–76 ] This paper reviews calibration methods developed by different NMIs and research groups for SPDs, along with the uncertainty achieved.…”

Determination of the contributions of degenerate and non-degenerate two-photon absorption response in silicon avalanche photodiode for infrared photon detection

“…The frequency upconversion scheme is based on the sum-frequency generation process where the wavelength of the signal photons is transformed into the shorter wavelength region with the preservation of all the quantum characteristics and the upconverted photons finally impinge on the active area of a silicon-based detector for detection [9,10]. However, in the frequency upconversion system, special nonlinear crystals are designed and cut to fulfill the phase-matching conditions by adjusting the tilting angle and the operation temperature to maintain the momentum conservation for a high conversion efficiency [11][12][13][14]. At the same time, the TPA effect caused by the free electron in a semiconductor photodetector that absorbs two photons simultaneously, thereby achieving a transition from the ground state to the excited state and releasing a photoelectron by returning to the ground state can also be used for the detection of infrared photons [15,16].…”