Grating Assisted Hybrid Plasmonic Grating Slot Waveguide for On-Chip Surface-Enhanced Raman Scattering Sensor

A dielectric slot Bragg grating is introduced into the hybrid plasmonic grating slot waveguide for secondary backward coupling and thereby further enhancing the electric field. The dielectric grating also acts as a notch filter, which can be used to filter out the pump light. Such grating-assisted configuration demonstrates a simple and universal approach for realizing a compact on-chip surface-enhanced Raman scattering (SERS) sensor with giant electric field enhancement and built-in filter.