Open AccessImpedance matching vertical optical waveguide couplers for dense high index contrast circuits
Author(s) -
Renren Sun,
Mark Beals,
Andrew Pomerene,
Jing Cheng,
Ching-yin Hong,
Lionel C. Kimerling,
Jürgen Michel
Publication year - 2008
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.16.011682
Subject(s) - power dividers and directional couplers , optics , waveguide , materials science , impedance matching , refractive index , hybrid coupler , silicon on insulator , coupling (piping) , optoelectronics , electrical impedance , silicon , physics , quantum mechanics , metallurgy
We designed and demonstrated a compact, high-index contrast (HIC) vertical waveguide coupler for TE single mode operation with the lowest coupling loss of 0.20 dB +/- 0.05 dB at 1550 nm. Our vertical coupler consists of a pair of vertically overlapping inverse taper structures made of SOI and amorphous silicon. The vertical coupler can suppress power oscillation observed in regular directional couplers and guarantees vertical optical impedance matching with great tolerance for fabrication and refractive index variations of the waveguide materials. The coupler furthermore shows excellent broadband coupling efficiencies between 1460 nm and 1570 nm.