Optical fiber tip: Nanotweezer, nanoantenna and plasmonic hotspot

We have introduced a technique to grow novel optical fiber tip (OFT) which can be widely used in nano-photonics research. It takes help of capillary action and surface tension meniscus of hydrofluoric acid (HF) around the fiber during etching process to grow ultrafine OFT. The optical fiber used has different core material, which is etched at higher rate in HF compared to its cladding. The optical properties of the probe makes the tip very attractive as nano-optical tweezer, optical nanoantenna, probe for surface enhanced and tip enhanced Raman scattering (SERS and TERS) etc. The nano structure is also very effective for higher harmonic generation. To validate our claim we have explored few applications of the OFT, such as Bessel beam generation, second harmonic generation (SHG), optical tweezer and optical nanoantenna generating plasmonic hotspot.