1. Suppressing Dark Counts of Multimode-Fiber-Coupled Superconducting Nanowire Single-Photon Detector
- Author
-
Heqing Wang, Xiaoming Xie, Chaolin Lv, Jia Huang, Xing-Qu Sun, Xiao-Yu Liu, Zhang Weijun, Zhen Wang, Chengjun Zhang, Hao Li, Hui Zhou, and Lixing You
- Subjects
lcsh:Applied optics. Photonics ,Materials science ,Multi-mode optical fiber ,business.industry ,Detector ,lcsh:TA1501-1820 ,Superconducting nanowire single-photon detector ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,010309 optics ,Wavelength ,0103 physical sciences ,Transmittance ,lcsh:QC350-467 ,Optoelectronics ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Optical filter ,Noise-equivalent power ,Passband ,lcsh:Optics. Light - Abstract
Large active-area superconducting nanowire single-photon detectors (SNSPDs) coupled with multimode fibers (MMFs) can provide high light-gathering capacity, which is essential for free-space detection applications in photon-starved regimes. However, MMF-coupled SNSPDs often suffer from large system dark count rates (DCRsys) over kHz due to blackbody radiation of the MMF at room temperature. Such large DCRsys would significantly degrade signal-to-noise ratio (SNR) of the receiving system. This paper reports an MMF-coupled large-active-area SNSPD system with low DCRsys by using a homemade cryogenic MMF filter bench. The filter bench, which consists of lenses and optical filters, can provide a high transmittance of about 80% at the central wavelength of the passband (1550 ± 12.5 nm) and a wide blocking range from 500 nm to over 6000 nm at 40 K. With using the filter bench, the DCRsys of an MMF-coupled 9-pixel SNSPD array with an active area of 50 μm in diameter is greatly suppressed by 23 dB with 1 dB loss of system detection efficiency (SDE). The detector demonstrates an SDE of 51% at a DCRsys of 100 Hz for 1550 nm photons. Thus, SNR of the detector is enhanced by about 160 times and the noise equivalent power is improved to 3×10-19 W/Hz1/2.
- Published
- 2019