Open AccessUltra‐compact and ultra‐broadband hybrid plasmonic‐photonic vertical coupler with high coupling efficiency, directivity, and polarisation extinction ratio
Author(s) -
Pezeshki Hamed,
Wright Amanda J.,
Larkins Eric C.
Publication year - 2022
Publication title -
iet optoelectronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.379
H-Index - 42
eISSN - 1751-8776
pISSN - 1751-8768
DOI - 10.1049/ote2.12063
Subject(s) - directivity , extinction ratio , plasmon , optics , photonic integrated circuit , photonics , power dividers and directional couplers , materials science , optoelectronics , silicon on insulator , broadband , wavelength , physics , silicon , telecommunications , antenna (radio) , computer science
An ultra‐compact, ultra‐broadband vertical coupler for dense photonic integrated circuits is reported with a 1.07 × 0.62 μm 2 wavelength‐scale footprint. This hybrid plasmonic‐photonic coupler uses a unique two‐plane plasmonic nanoantenna array on a silicon‐on‐insulator waveguide. The in‐ and out‐of‐plane interference of the multipole moments and dual‐feed nanoantennas results in efficient, unidirectional coupling. Finite‐element simulations show that, for a 0.8 μm diameter Gaussian beam, the maximum coupling efficiency (CE) is −3.4 dB across the telecommunication C‐, L‐ and U‐bands with a 3‐dB bandwidth of 230 nm. The CE is > 9 dB higher than recently reported ultra‐compact plasmonic couplers. The maximum directivity and polarisation extinction ratio across the C‐ to U‐bands are 9.2 and 24.1 dB, respectively. Finally, as an out‐coupler, it has a vertical directivity of >8.5 dB, enabling its use for vertical optical interconnects between two vertically separated circuits.