Superconducting Nanowire Single Photon Detector with Optical Cavity

• 来源期刊: 中国物理快报（英文版）
• 关键词: @@
• 年，卷（期）: 2016,（8）
• 页码范围: 143-145
• 页数: 3页
• 语种: 中文
• DOI: 10.1088/0256-307X/33/8/088502

摘要

Increasing the detection efficiency (DE) is a hot issue in the development of the superconducting nanowire single photon detector (SNSPD).In this work,a cavity-integrated structure coupled to the SNSPD is used to enhance the light absorption of nanowire.Ultra-thin Nb films are successfully prepared by magnetron sputtering,which are used to fabricate Nb/Al SNSPD with the curve of 100nm and the square area of 4 × 4 μm2 by sputtering and the lift-off method.To characterize the optical and electrical performance of the cavity-integrated SNSPD,a reliable cryogenic research system is built up based on a He3 system.To satisfy the need of light coupling,a packaging structure with collimator is conducted.Both DE and the dark count rates increase with Ib.It is also found that the DE of SNSPD with cavities can be up to 0.17％ at the temperature of 0.7K under the infrared light of 1550nm,which is obviously higher than that of the SNSPD directly fabricated upon silicon without any cavity structure.