Karl Philipp, Mennle Sandra, Ubl Monika, Flad Philipp, Yang Jing-Wei, Peng Tzu-Yu, Lu Yu-Jung, Giessen Harald
Opt Express. 2021 May 24;29(11):17087-17096. doi: 10.1364/OE.424148.
Quantum technologies such as quantum computing and quantum cryptography exhibit rapid progress. This requires the provision of high-quality photodetectors and the ability to efficiently detect single photons. Hence, conventional avalanche photodiodes for single photon detection are not the first choice anymore. A better alternative are superconducting nanowire single photon detectors, which use the superconducting to normal conductance phase transition. One big challenge is to reduce the product between recovery time and detection efficiency. To address this problem, we enhance the absorption using resonant plasmonic perfect absorber effects, to reach near-100% absorption over small areas. This is aided by the high resonant absorption cross section and the angle insensitivity of plasmonic resonances. In this work we present a superconducting niobium nitride plasmonic perfect absorber structure and use its tunable plasmonic resonance to create a polarization dependent photodetector with near-100% absorption efficiency in the infrared spectral range. Further we fabricated a detector and investigated its response to an external light source. We also demonstrate the resonant plasmonic behavior which manifests itself through a polarization dependence detector response.
量子计算和量子密码学等量子技术正取得飞速进展。这就需要提供高质量的光电探测器以及高效探测单光子的能力。因此，用于单光子探测的传统雪崩光电二极管已不再是首选。更好的选择是超导纳米线单光子探测器，它利用超导到正常导电的相变。一个重大挑战是降低恢复时间与探测效率之间的乘积。为解决这个问题，我们利用共振等离子体完美吸收体效应增强吸收，在小面积上实现近100%的吸收。这得益于高共振吸收截面和等离子体共振的角度不敏感性。在这项工作中，我们展示了一种超导氮化铌等离子体完美吸收体结构，并利用其可调谐的等离子体共振来制造在红外光谱范围内具有近100%吸收效率的偏振依赖型光电探测器。此外，我们制造了一个探测器并研究了它对外部光源的响应。我们还展示了通过偏振依赖型探测器响应表现出来的共振等离子体行为。
