Azimuthal vector beam illuminating plasmonic tips circular cluster for surface-enhanced Raman spectroscopy

Noble metallic nanostructures with strong electric near-field enhancement can significantly improve nanoscale light–matter interactions and are critical for high-sensitivity surface-enhanced Raman spectroscopy (SERS). Here, we use an azimuthal vector beam (AVB) to illuminate the plasmonic tips circular cluster (PTCC) array enhance intensity of PTCC array, then it SERS sensitivity. The was prepared based on self-assembled inductive coupled plasmon (ICP) etching methods. calculation results show that, compared linearly polarized (LPB) radial excitations, AVB excitation obtain stronger due resonant responses formed in nanogap between adjacent tips. Subsequently, our experimental proved that increased sensitivity 10-13 mol/L, which is two orders magnitude higher than LPB excitation. Meanwhile, had excellent uniformity factor calculated be ∼2.4×108. This kind light field enhancing may applied sensing technologies, such as trace amount detection.