Novel surface plasmon waveguide for high integration

TLDR

A novel surface plasmon waveguide structure is proposed to enable highly integrated planar lightwave circuits. The design uses a trench etched through a metallic thin film on silica to confine light, and numerical studies examine mode properties, inter‑waveguide coupling, and 90° bending. The structure supports sharp 90° bends, high integration, and is easier to fabricate, though polymer upper‑cladding is required.

Abstract

A novel surface plasmon waveguide structure is proposed for highly integrated planar lightwave circuits. By etching a small trench through a metallic thin film on a silica substrate, a guided mode with highly confined light fields is realized. The mode properties of the proposed structure are studied. The necessity of using a polymer upper-cladding is discussed. The coupling between two closely positioned waveguides and a 90o bending are also studied numerically. Sharp bending and high integration can be realized with the present surface plasmon waveguide. The proposed structure is easy to fabricate as compared with some other types of surface plasmon waveguides for high integration.