High-speed SNSPD with high-absorption structure and preparation method of high-speed SNSPD

Abstract

The invention discloses high-speed SNSPD with a high-absorption structure and a preparation method of the high-speed SNSPD. The SNSPD is based on a high-refraction-index incident medium and an air cavity structure, and can further improve the photon absorption rate of superconducting nanowire, and compared with the prior art, the SNSPD can achieves approximate 100 percent absorption rate with lower duty ratio in the condition of nanowire made of superconducting ultrathin membrane made of the same material and having the same thickness, so that the difficulty in electron beam lithography steps is greatly lowered, the SNSPD is beneficial to the preparation of superfine nanowire, the high-quality growth of superconducting films can be guaranteed through the adoption of an SOI substrate, the intrinsic quantum efficiency of a detector is not affected; moreover, the highest counting rate of the detector can be enhanced as the total length of the required nanowire is obviously reduced in the condition that the same effective detection area is guaranteed, and the probability of defect occurrence during the preparation process is obviously reduced.

Description

technical field [0001] The invention belongs to the field of single-photon detection, is suitable for realizing ultra-fast and high-efficiency single-photon detection in the near-infrared band, and relates to a high-speed SNSPD with a strong absorption structure and a preparation method thereof. Background technique [0002] In recent years, G.N.Gol'tsman et al., "Picosecond superconducting single-photon optical detector," Applied Physics Letter, vol.79, pp.705–707, 2001. Recorded superconducting nanowire single-photon detector (SNSPD) , due to its excellent single-photon detection ability in the visible and infrared bands, ultra-high count rate, low dark count, and small time jitter, it has attracted more and more attention, especially its quantum Both the efficiency and the highest count rate have surpassed the existing avalanche photodiodes based on compound semiconductor materials, making them the most powerful candidate detectors in the fields of quantum communication a...

AI Technical Summary

Problems solved by technology

If you want to further increase the absorption rate, you need to increase the duty cycle or thickness of the nanowire, but the former puts forward more stringent requirements on sample preparation, while the latter will lead to a decrease in the intrinsic quantum efficiency of the detector.

US2012 / 0077680A1 "Nanowire-based detector" K.K.Berggren, X.Hu, D.Masciarelli et al. The method of increasing the absorption rate based on nano-antennas can be realized under the conditions of 4nm thick and 50% duty cycle NbN nanowires. The absorption rate is close to 100%, but this scheme also puts forward relatively high requirements on sample preparation, and the final experimental results show that its yield is not high

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