Self-cleaning optical fiber can help in monitoring environment and diagnosing cancer

Tampere University.

A novel optical fiber design has been developed by researchers at Tampere University. The self-cleaning beam of the new optical fiber can be used to develop applications such as pollutant tagging, cancer diagnostics, environmental monitoring, and food control. The journal Nature Communications published the finding.

When a high-powered ultra short pulse of light interacts with a material such as a glass optical fiber, a range of highly nonlinear interactions take place that cause complex changes in the temporal and spectral properties of the injected light. When taken to the extreme, such interactions can lead to the creation of a rainbow laser of light. Since the first demonstration of a special type of optical fiber in 2000, supercontinuum laser light has changed many areas of science.

The current problem with current supercontinuum sources is that they are based on optical fibers that do not support a single mode, which limits their optical power. Conventional optical fibers are made of glass and have a limited transmission range. Soft glasses, which are used for optical fibers, have a lower damage threshold than silica, which limits the power of the supercontinuum beam.

A self-cleaning beam with a non-silica optical fiber.

A different type of optical fiber with a Refractive index that varies continuously across the fiber structure has been shown to yield a dramatic increase in supercontinuum power, while still preserving a smooth beam intensity profile. A clean beam profile and high power supercontinuum light are produced by this self-cleaning mechanism. As well as their many applications, they also provide a means of studying fundamental physics effects such as wave turbulence.

The use of these fibers has been restricted to the visible and near-IR, since they have recently attracted attention from the research community. The group of Profs collaborated. The group of Prof. Dudley at the University of Burgundy demonstrated for the first time the generation of a two-octave supercontinuum.

This problem has been solved by using a particular design that utilizes two types of lead-bismuth-Gallate glass rods with different Refractive index drawn to yield a core. Zahra Eslami says that the graded-index fiber has an effective parabolic Refractive index profile with transmission up to the mid-infrared and enhanced light-matter interactions.

Diagnostic and monitoring have great potential.

The mid-infrared contains the characteristic transitions of many important molecules.

The novel solution will lead to more efficient supercontinuum light sources in the mid-infrared with many potential applications.

The researchers think that this novel type of fiber will soon become a standard material for the generation of broadband sources and frequency combs.

More information: Zahra Eslami et al, Two octave supercontinuum generation in a non-silica graded-index multimode fiber, Nature Communications (2022). DOI: 10.1038/s41467-022-29776-6 Journal information: Nature Communications Provided by Tampere University Citation: Self-cleaning optical fiber can help in monitoring environment and diagnosing cancer (2022, April 26) retrieved 26 April 2022 from https://phys.org/news/2022-04-self-cleaning-optical-fiber-environment-cancer.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.