title: Ultracompact low-loss coupler between strip and slot waveguides.
abstract: We present both theoretical and experimental results of an ultracompact waveguide coupler that is capable of highly efficient coupling of light from strip waveguides to slot waveguides, and vice versa. By optimizing the geometrical parameters, it is possible to achieve extremely low-loss coupling. A coupling efficiency of 97% has been obtained experimentally while keeping the overall size down to the range below 10 mum. Further analysis shows that the proposed coupler has relatively high tolerance to fabrication errors and is wavelength insensitive.
authors.affiliation: JORCEP [Joint Research Center of Photonics of the Royal Institute of Technology (Sweden) and Zhejiang University], Zhejiang University, Hangzhou 310058, China. Zhechao@kth.se
authors.forename: Zhechao
authors.initials: Z
authors.lastname: Wang
authors.forename: Ning
authors.initials: N
authors.lastname: Zhu
authors.forename: Yongbo
authors.initials: Y
authors.lastname: Tang
authors.forename: Lech
authors.initials: L
authors.lastname: Wosinski
authors.forename: Daoxin
authors.initials: D
authors.lastname: Dai
authors.forename: Sailing
authors.initials: S
authors.lastname: He