Statistical analysis of the temporal single-photon response of superconducting nanowire single photon detection

We demonstrate a photon-counting chirped amplitude modulation (CAM) light detection and ranging (lidar) system incorporating a superconducting nanowire single-photon detector (SNSPD) and operated at a wavelength of 1550 nm. The distance accuracy of the lidar system was determined by the CAM bandwidth and signal-to-noise ratio (SNR) of an intermediate frequency (IF) signal. Owing to a short dead time (10 ns) and negligible dark count rate (70 Hz) of the SNSPD, the obtained IF signal attained an SNR of 42 dB and the direct distance accuracy was improved to 3 mm when the modulation bandwidth of the CAM signal was 240 MHz and the modulation period was 1 ms.

Section: Methodsmentioning

confidence: 99%

Photon-counting chirped amplitude modulation lidar system using superconducting nanowire single-photon detector at 1550-nm wavelength

Zhou

Lü

et al. 2018

“…Because of its high thermal sensitivity, it has wide applications in many areas, including single photon detectors from near-infrared to γ-ray, cosmic microwave background bolometers, and dark matter detectors. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] The T c of a bilayer superconducting thin film system could be tuned in a well controlled way by just tuning the thickness ratio of the two elements. Many bilayer systems, such as Mo/Au, Mo/Cu, Ti/Au, and Ti/Al systems, [1,11,[16][17][18][19][20][21] have been chosen for fabricating the TESs.…”

Section: Introductionmentioning

confidence: 99%

Superconductivity of bilayer titanium/indium thin film grown on SiO ₂ /Si (001)

Lü

Liu

et al. 2018

Bilayer superconducting films with tunable transition temperature (T c ) are a critical ingredient to the fabrication of high-performance transition edge sensors. Commonly chosen materials include Mo/Au, Mo/Cu, Ti/Au, and Ti/Al systems. Here in this work, titanium/indium (Ti/In) bilayer superconducting films are successfully fabricated on SiO 2 /Si (001) substrates by molecular beam epitaxy (MBE). The success in the epitaxial growth of indium on titanium is achieved by lowering the substrate temperature to −150 • C during indium evaporation. We measure the critical temperature under a bias current of 10 µA, and obtain different superconducting transition temperatures ranging from 645 mK to 2.7 K by adjusting the thickness ratio of Ti/In. Our results demonstrate that the transition temperature decreases as the thickness ratio of Ti/In increases.

“…[1][2][3][4] Single photon detectors have been widely used in many weak signal detection fields, such as remote sensing, biological imaging through highly scattering and absorbing tissues, weak fluorescence imaging, and so on. [5][6][7][8][9][10][11] One of the leading applications is remote ranging and imaging with high accuracy. A Geiger mode Avalanche Photodiode Detector (Gm-APD), as one of the single photon detectors, was applied in a lidar system for the first time by MIT Lincoln Laboratories in the JIGSAW project.…”

Section: Introductionmentioning

confidence: 99%

The intensity detection of single-photon detectors based on photon counting probability density statistics

Zhang¹,

Wu²,

Song³

et al. 2017

Single-photon detectors possess the ultra-high sensitivity, but they cannot directly respond to signal intensity. Conventional methods adopt sampling gates with fixed width and count the triggered number of sampling gates, which is capable of obtaining photon counting probability to estimate the echo signal intensity. In this paper, we not only count the number of triggered sampling gates, but also record the triggered time position of photon counting pulses. The photon counting probability density distribution is obtained through the statistics of a series of the triggered time positions. Then Minimum Variance Unbiased Estimation (MVUE) method is used to estimate the echo signal intensity. Compared with conventional methods, this method can improve the estimation accuracy of echo signal intensity due to the acquisition of more detected information. Finally, a proof-of-principle laboratory system is established. The estimation accuracy of echo signal intensity is discussed and a high accuracy intensity image is acquired under low-light level environments.