Superconducting nanowire single-photon detectors with non-periodic dielectric multilayers

Abstract

We present superconducting nanowire single-photon detectors (SSPDs) on non-periodic dielectric multilayers, which enable us to design a variety of wavelength dependences of optical absorptance by optimizing the dielectric multilayer. By adopting a robust simulation to optimize the dielectric multilayer, we designed three types of SSPDs with target wavelengths of 500 nm, 800 nm, and telecom range respectively. We fabricated SSPDs based on the optimized designs for 500 and 800 nm, and evaluated the system detection efficiency at various wavelengths. The results obtained confirm that the designed SSPDs with non-periodic dielectric multilayers worked well. This versatile device structure can be effective for multidisciplinary applications in fields such as the life sciences and remote sensing that require high efficiency over a precise spectral range and strong signal rejection at other wavelengths.

Superior properties in room-temperature colloidal-dot quantum emitters revealed by ultralow-dark-count detections of temporally-purified single photons

“…This issue can be addressed by using superconducting-nanowire single-photon detectors (SSPDs), whose dark counts are much smaller than those of conventional detectors. While SSPDs are usually designed for the infrared region, we recently reported an SSPD design with high detection efficiencies in the visible region 43 . By using such SSPDs, the properties of room-temperature SPSs, which are easily obscured by the dark counts of detectors, may be revealed.…”

Recent Progress and Application of Superconducting Nanowire Single-Photon Detectors

“…It has been shown that the extrinsic DCR could be reduced by using cold optical bending fiber [29]. Furthermore, SSPDs with a dielectric multilayer designed to cut the extrinsic DCR also have been presented [31], [32].…”

“…Maximization of the optical absorbance at the desired wavelength was achieved by optically designing a dielectric mirror consisting of multilayers of two kinds of dielectric materials, such as SiO 2 and TiO 2 , on the substrate. More recently, a nonperiodic dielectric multilayer structure enabling the flexible spectrum (wavelength dependence) design of the optical absorbance in the SSPD was presented [32]. In shortwavelength applications, such as those in the life sciences, a multimode (MM) fiber with a large core is often used to introduce free-space light efficiently.…”

“…Especially, shorter wavelength photons can be detected easier than telecom photons because the higher energy photons can destroy the superconducting state of the nanowire more effectively. Recently, excellent SDEs of around 80% have been reported for various wavelengths ranging from visible (∼500 nm) to near infrared (∼1000 nm) [8], [32]- [35]. Maximization of the optical absorbance at the desired wavelength was achieved by optically designing a dielectric mirror consisting of multilayers of two kinds of dielectric materials, such as SiO 2 and TiO 2 , on the substrate.…”

Quest towards ultimate performance in superconducting nanowire single photon detectors

“…The optical cavity design has evolved through various ap-*Corresponding author (email: s-miki@nict.go.jp) proaches aimed at obtaining higher η abs : double-side cavity for back side illumination [6,7], optimized optical cavity for front side illumination [8], and cavity with distribution Bragg reflector (DBR) [9][10][11]. It is to be noted that such interesting approaches also made additional attempts to obtain the flexible wavelength spectrum by employing nonperiodic DBR [12], and to reduce the polarization sensitivity by optimizing the optical cavity design [13].Considerable attention has also been focused on obtaining an η int that is as high as possible. Among various approaches aimed at increasing η int , exploration of the optimal superconducting material is one of the most interesting topic.…”