Low-loss InP-based hybrid plasmonic waveguide

Abstract

In this article, a new structure of InP-based hybrid plasmonic waveguide (HPWG) has been proposed. The proposed HPWG shows a propagation length of at least 100 µm for 100 nm waveguide ridge width, twice the propagation length of the comparable silicon-on-insulator (SOI) based HPWG. This structure is compatible to the generic InP-based layer stack and suitable for monolithic integration with active devices such as laser and photodetector at 1.55 µm wavelength. This layer structure can be potentially utilized in future ultra-dense nanoscale photonic integrated circuits instead of SOI-based HPWG. A directional coupler power splitter is also investigated with the proposed HPWG structure showing a coupling length of less than 2 µm with a transmission of 98.7% and insertion loss of about 0.02 dB for a waveguide width and gap width of 200 nm and 50 nm, respectively.