Near-field plasmonic enhancement via nanogratings on hollow pyramidal aperture probe tip

We present the design of hollow near-field scanning microscope (NSOM) probe with nanogratings-on-tip to transport and concentrate localized surface plasmonic polariton (SPP) wave. By adding nano-grooves started from the intensity-maximum locations of lowest transmission mode and with pitch period supporting the metal-air interface SPP mode, the power throughput is increased at over 530 times comparing with single aperture probe with 405 nm source and 100 nm diameter aperture size. Two types of nanograting probe designs are chosen for fabrication and the power enhancement comparison is examined by probing the near-field fluorescent intensity of excited uniform quantum dots (QDs) layer via micro-contact printing method.