Improvement of infrared single-photon detectors absorptance by integrated plasmonic structures.
Plasmonic structures open novel avenues in photodetector development. Optimized illumination configurations are reported to improve p-polarized light absorptance in superconducting-nanowire single-photon detectors (SNSPDs) comprising short- and long-periodic niobium-nitride (NbN) stripe-patterns. In OC-SNSPDs consisting of ~quarter-wavelength dielectric layer closed by a gold reflector the highest absorptance is attainable at perpendicular incidence onto NbN patterns in P-orientation due to E-field concentration at the bottom of nano-cavities. In NCAI-SNSPDs integrated with nano-cavity-arrays consisting of vertical and horizontal gold segments off-axis illumination in S-orientation results in polar-angle-independent perfect absorptance via collective resonances in short-periodic design, while in long-periodic NCAI-SNSPDs grating-coupled surface waves promote EM-field transportation to the NbN stripes and result in local absorptance maxima. In NCDAI-SNSPDs integrated with nano-cavity-deflector-array consisting of longer vertical gold segments large absorptance maxima appear in 3p-periodic designs due to E-field enhancement via grating-coupled surface waves synchronized with the NbN stripes in S-orientation, which enable to compensate fill-factor-related retrogression.
Massachusetts Institute of Technology, Research Laboratory of Electronics, 77 Massachusetts Avenue, Cambridge, MA 02139, USA. mcsete@physx.u-szeged.hu
Mária
M
Csete
Aron
A
Sipos
Anikó
A
Szalai
Faraz
F
Najafi
Gábor
G
Szabó
Karl K
KK
Berggren
D000042:Absorption; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007259:Infrared Rays; D036103:Nanotechnology / Q000295:instrumentation*; D010783:Photometry / Q000295:instrumentation*; D017785:Photons; D020349:Surface Plasmon Resonance / Q000295:instrumentation*; D018511:Systems Integration