Electric field enhancement with plasmonic colloidal nanoantennas excited by a silicon nitride waveguide

TL;DR

This paper demonstrates that CMOS-compatible silicon nitride waveguides can excite plasmonic nanoantennas, achieving significant local electric field enhancement for integrated spectroscopy applications.

Contribution

It introduces a method to achieve local field enhancement using colloidal plasmonic nanosphere dimers on silicon nitride waveguides, advancing integrated optical sensing technology.

Findings

100-fold electric field enhancement in dimer gap

Field enhancement depends on dimer position and orientation

Simulation results support feasibility for integrated spectroscopy

Abstract

We investigate the feasibility of CMOS-compatible optical structures to develop novel integrated spectroscopy systems. We show that local field enhancement is achievable utilizing dimers of plasmonic nanospheres that can be assembled from colloidal solutions on top of a CMOS-compatible optical waveguide. The resonant dimer nanoantennas are excited by modes guided in the integrated silicon nitride waveguide. Simulations show that 100 fold electric field enhancement builds up in the dimer gap as compared to the waveguide evanescent field amplitude at the same location. We investigate how the field enhancement depends on dimer location, orientation, distance and excited waveguide modes.