Wuytens Pieter C, Skirtach Andre G, Baets Roel
Opt Express. 2017 May 29;25(11):12926-12934. doi: 10.1364/OE.25.012926.
A hybrid integration of nanoplasmonic antennas with silicon nitride waveguides enables miniaturized chips for surface-enhanced Raman spectroscopy at visible and near-infrared wavelengths. This integration can result in high-throughput SERS assays on low sampling volumes. However, current fabrication methods are complex and rely on electron-beam lithography, thereby obstructing the full use of an integrated photonics platform. Here, we demonstrate the electron-beam-free fabrication of gold nanotriangles on deep-UV patterned silicon nitride waveguides using nanosphere lithography. The localized surface-plasmon resonance of these nanotriangles is optimized for Raman excitation at 785 nm, resulting in a SERS substrate enhancement factor of 2.5 × 10. Furthermore, the SERS signal excited and collected through the waveguide is as strong as the free-space excited and collected signal through a high NA objective.
将纳米等离子体天线与氮化硅波导进行混合集成，能够实现用于可见和近红外波长表面增强拉曼光谱的小型化芯片。这种集成可在低采样体积下实现高通量表面增强拉曼光谱分析。然而，当前的制造方法复杂且依赖电子束光刻，从而阻碍了集成光子学平台的充分利用。在此，我们展示了使用纳米球光刻技术在深紫外图案化的氮化硅波导上无电子束制造金纳米三角形。这些纳米三角形的局域表面等离子体共振针对785nm的拉曼激发进行了优化，产生了2.5×10的表面增强拉曼光谱基底增强因子。此外，通过波导激发和收集的表面增强拉曼光谱信号与通过高数值孔径物镜在自由空间激发和收集的信号一样强。
