Effect of etching depth on the performance of InP-based hybrid plasmonic waveguides

Hybrid plasmonic (HP) waveguides have attracted a lot of attention in recent years for its ability to provide long propagation length along with subwavelength confinement. In this study, the effect of InGaAsP(Q) layer etch depth on an InP-based HP-waveguide was investigated. Then, the layer thicknesses were optimized to achieve a maximum propagation length of 80 µm and the minimum effective area of 0.03 µm2 indicating a significant improvement compared to previous studies. Meanwhile, the coupling length of a directional coupler for various etch depth was calculated. Finally, the effect of the etch depth on the optical power transmission of the 90° curved waveguide and coupling between the curved and straight waveguides were determined.