Low‐loss indium phosphide‐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 and 50 nm, respectively.