Photonic crystal formation on optical nanofibers using femtosecond laser ablation technique

TL;DR

This paper reports the fabrication of photonic crystal structures on optical nanofibers using a single femtosecond laser pulse, leveraging the fiber's lensing effect to create periodic nano-craters that enhance field confinement for nanophotonics.

Contribution

It introduces a novel femtosecond laser ablation method to create 1-D photonic crystals on nanofibers, enabling new applications in nanophotonics and quantum information.

Findings

Thousands of nano-craters formed with a single pulse

Nanofiber acts as a cylindrical lens focusing the laser

Photonic crystal structures enhance field confinement

Abstract

We demonstrate that thousands of periodic nano-craters are fabricated on a subwavelength-diameter tapered optical fiber, an optical nanofiber, by irradiating with just a single femtosecond laser pulse. A key aspect of the fabrication is that the nanofiber itself acts as a cylindrical lens and focuses the femtosecond laser beam on its shadow surface. We also demonstrate that such periodic structures on the nanofiber, act as a 1-D photonic crystal (PhC). Such PhC structures on the nanofiber will strongly enhance the field confinement in such a tapered fiber-based system and may open new avenues in nanophotonics and quantum information technology.