Non-destructive profilometry of optical nanofibres

TL;DR

This paper introduces a non-destructive, high-precision optical scattering scanning method for profiling optical nanofibres, enabling rapid, sub-nanometre resolution measurements during fabrication.

Contribution

The authors develop a simple, non-invasive scattering technique using a probe nanofibre to accurately measure nanofibre profiles in real-time, compatible with standard fibre puller setups.

Findings

Achieved sub-nanometre radial resolution at 0.7 nm in 10 ms

Enabled complete nanofibre profile measurement within minutes

Demonstrated applicability to various optical nanofibre applications

Abstract

Single-mode optical nanofibres are a central component of a broad range of applications and emerging technologies. Their fabrication has been extensively studied over the past decade, but imaging of the final sub-micrometre products has been restricted to destructive or low-precision techniques. Here we demonstrate an optical scattering-based scanning method that uses a probe nanofibre to locally scatter the evanescent field of a sample nanofibre. The method does not damage the sample nanofibre and is easily implemented only using the same equipment as in a standard fibre puller setup. We demonstrate sub-nanometre radial resolution at video rates (0.7 nm in 10 ms) on single mode nanofibres, allowing for a complete high-precision profile to be obtained within minutes of fabrication. The method thus enables non-destructive, fast and precise characterisation of optical nanofibers, with applications ranging from optical sensors and cold atom traps to non-linear optics.