Water Fibers

TL;DR

This paper introduces water-based fibers that can confine both capillary and electromagnetic oscillations, enabling new optofluidic applications with enhanced sensitivity and compatibility with water.

Contribution

The authors fabricate water fibers bridging optical couplers, demonstrating their ability to confine oscillations and record vibrations, pioneering a new class of micro-electro-capillary systems.

Findings

Water fibers can be longer than a millimeter.

They can record audible vibrations including harmonics.

Water fibers are compatible with biological liquids.

Abstract

Fibers constitute the backbone of modern communication and are used in laser surgeries; fibers also genarate coherent X-ray, guided-sound and supercontinuum. In contrast, fibers for capillary oscillations, which are unique to liquids, were rarely considered in optofluidics. Here we fabricate fibers by water bridging an optical tapered-coupler to a microlensed coupler. Our water fibers are held in air and their length can be longer than a millimeter. These hybrid fibers co-confine two important oscillations in nature: capillary- and electromagnetic-. We optically record vibrations in the water fiber, including an audio-rate fundamental and its 3 overtones in a harmonic series, that one can hear in soundtracks attached. Transforming Micro-Electro-Mechanical-Systems [MEMS] to Micro-Electro-Capillary-Systems [MECS], boosts the device softness by a million to accordingly improve its response to minute forces. Furthermore, MECS are compatible with water, which is a most important liquid in our world.