Inne wydarzenia

Abstract:

Superconducting nanowire based single photon detectors are made from thin superconducting nanowires operated at a bias current slightly too small to cause the breakdown of the superconductivity. An additionally absorbed single photon is able to do so. It causes with that an electrical signal that can be read-out externally. These click-detectors can be integrated into photonic chips where the evanescent coupling to an optical waveguide over an extended spatial region allows for near-unity efficiency. However, the length of these nanowires precludes a short response time that is important for many applications.

Here, I will describe our work in where we’ve integrated such single photon detectors into photonic crystal based cavities to solve this issue and to make available ultrafast (times scales in the order of 100 ps) and high efficiency (70%) single photon detectors. I present different generations of devices where we exploit (a) the concept of a perfect absorber in the design of the photonic crystal cavity [1] and (b) the concept of critical coupling [2]. I put emphasis on detailing the design principles and the numerical analysis of the elements but I also present fabricated devices and describe their optical and electrical characterization. Indications on further developments are given such as, e.g., how such architectures can be enhanced towards single photon spectrometers [3].

References:

[1] A. Vetter, S. Ferrari, P. Rath, R. Alaee, O. Kahl, V. Kovalyuk, S. Diewald, G. N. Goltsman, A. Korneev, C. Rockstuhl, and W. H. P. Pernice, “Cavity-Enhanced and Ultrafast Superconducting Single-Photon Detectors” Nano Letters Vol. 16 7085, (2016)
[2] J. Münzberg, A. Vetter, F. Beutel, W. Hartmann, S. Ferrari, W. H. P. Pernice, and C. Rockstuhl, “Superconducting nanowire single-photon detector implemented in a 2D photonic crystal cavity” Optica Vol. 39 045303, (2018)
[3] Y. Yun, A. Vetter, R. Stegmueller, S. Ferrari, W. H. P. Pernice, C. Rockstuhl, and C. Lee, “Superconducting-Nanowire Single-Photon Spectrometer Exploiting Cascaded Photonic Crystal Cavities” Physical Review Applied Vol. 13 014061, (2020)