We propose a simple optical fiber tip for field-enhanced second harmonic generation (SHG). The tip shows nonlinear phenomena of SHG over a wide range of sources, at least from 630 to 830 nm. The optical field corresponding to the second harmonic appears as a nondiffracting bottle beam with voids due to the surface curvature of the tip. The field-enhanced second harmonic can also induce surface plasmons, converting the tip to a plasmonic probe with reduced background signal. The tip can be useful in nanophotonics characterization. As an example, we demonstrate the tip’s response as a surface-enhanced Raman spectroscopy probe.
© 2012 Optical Society of America
Optical Design and Fabrication
Original Manuscript: August 17, 2012
Revised Manuscript: August 24, 2012
Manuscript Accepted: August 24, 2012
Published: September 20, 2012
Sudipta Sarkar Pal, Samir K. Mondal, Phun Phun Bajpai, and Pawan Kapur, "Optical fiber tip for field-enhanced second harmonic generation," Opt. Lett. 37, 4017-4019 (2012)