Resonant Cavity Enhanced On-Chip Raman Spectrometer Array with Precisely Positioned Metallic Nano-Gaps for Single Molecule Detection

摘要

During the Phase I program, our theoretical and experimental investigation has yielded fruitful results, which laid a solid foundation for the continuation of the Phase II program. From the design point of view, we designed ultra-compact highly reflective Si3N4 waveguide gratings with minimized side lobe reflection, and simulated the surface plasmonic resonance from metallic nanowires using 2-dimensional finite difference time domain (2-D FDTD) method. These simulation results have worked as the guideline for the Phase I experimental activities, and will continue to guide the Phase II program. In the aspects of device fabrication, we fabricated multi-segment gold nanowires with different diameters using electroplating, and formed nanogaps from 5nm to 50nm by sacrificial chemical etching. Surface enhanced Raman scattering (SERS) characterization using these gold nanowires with nanogaps are conducted to measure the Raman signals from Methylene Blue (MB) molecules.