A low-loss photonic silica nanofiber for higher-order modes

TL;DR

This paper demonstrates high-transmission, low-loss propagation of higher-order modes in a carefully designed silica nanofiber, enabling advanced nanophotonic device integration with minimal mode contamination.

Contribution

The authors present a method to achieve over 97% transmission of higher-order modes in a 350 nm radius nanofiber with precise taper control and a setup for selective mode launching.

Findings

>97% transmission of higher-order modes

Less than 1% fundamental mode contamination during launching

Good agreement between experiments and simulations

Abstract

Optical nanofibers confine light to subwavelength scales, and are of interest for the design, integration, and interconnection of nanophotonic devices. Here we demonstrate high transmission (> 97%) of the first family of excited modes through a 350 nm radius fiber, by appropriate choice of the fiber and precise control of the taper geometry. We can design the nanofibers so that these modes propagate with most of their energy outside the waist region. We also present an optical setup for selectively launching these modes with less than 1% fundamental mode contamination. Our experimental results are in good agreement with simulations of the propagation. Multimode optical nanofibers expand the photonic toolbox, and may aid in the realization of a fully integrated nanoscale device for communication science, laser science or other sensing applications.