High-efficiency Superconducting Single-photon Detectors
Thomas Gerrits, Adrian Lita, Varun Boehm Verma +4 more
Superconducting single-photon detectors have been shown to have extremely high detection efficiency over a large wavelength range, typically exceeding 90 % [1, 2]. Their use in quantum and classical optics is becoming more and more widespread in part due to improvements to and ease of use of the cryogenic packaging. In this talk, we will review two superconducting detector technologies, the superconducting nanowire single-photon detector (SNSPD) and the optical transition-edge sensor (TES) [3], that are being developed at NIST. We will also describe their applications in quantum and classical optics and present our recent effort to use these detectors as calibration standards, as well as our effort to establish a single-photon detector calibration service. Superconducting Nanowire Single Photon Detectors The SNSPD is based on a meandering, narrow, thin superconducting nanowire, current-biased close to its critical current. Our SNSPDs operate at temperatures around 1K. When a photon is absorbed in the detection region, the energy deposited drives the wire normal and a voltage pulse can be observed. Due to the speed of the detection process, the SNSPD offers high timing resolution along with detection of the photon flux at the shot-noise limit. The combination of both these features yields a detector that can measure the photon’s arrival time from a faint object or source. SNSPDs also offer single-photon detection capability beyond the wavelength detection range of silicon and InGaAs, out to at least 5000 nm [4]. SNSPDs were also recently implemented in an 8×8-pixel array enabling low-resolution, real-time imaging [5]. For our calibration service effort, we built an SNSPD system that can be used as a transfer standard between labs for single-photon detector calibrations. Transition Edge Sensors In contrast to the SNSPD, the TES is a photon-number resolving detector that has almost unity detection efficiency. The TES consists of a superconducting thin film, voltage-biased so that its resistance is in the transition between the superconducting regime and the normal conducting regime. The steep slope of the resistive transition allows for small temperature changes to be measured. The TES is designed such that the absorption of a single photon increases the temperature of the superconducting film enough to discern the resulting signal from the TES system noise. Therefore, the TES needs to be electrically and thermally quiet and is generally operated at temperatures around 100 mK. Due to its energy resolving capability, the TES can be also used as a spectrally resolving single-photon detector with limited resolution [6]. The TES can also be operated as a cryogenic radiometer in combination with an electrical substitution method, and can, in principle, yield absolute calibration of optical powers on the order of a few tens of femtowatts [7]. References 1 A. E. Lita, A. J. Miller, and S. W. Nam, Opt. Express 16, 3032 (2008). 2 F. Marsili, et al., Nat Photon 7, 210 (2013). 3 R. Hadfield and G. Johansson, Superconducting Devices in Quantum Optics (Springer, 2016). 4 F. Marsili, et al., in CLEO: 2013 (OSA, San Jose, California, 2013), p. CTu1H.1. 5 M. S. Allman, et al., Applied Physics Letters 106, 192601 (2015). 6 M. Fortsch, et al., Journal of Optics 17, 065501 (2015). 7 N. A. Tomlin, J. H. Lehman, and S. Nam, Optics Letters 37, 2346 (2012).
•Jan 1, 2018•0 citations