Research team achieves breakthroughs in precision measurement by 'scrambling' laser light

We can't perform accurate work in most circumstances. A team of researchers from the University of Adelaide and the University of St Andrew's, Scotland have achieved recent breakthrough in precision measurement by using laser light.

The leader of the team was Professor Kishan Dholakia, who is a professor at the School of Biological Sciences, University of Adelaide and the School of Physics and Astronomy.

He said that they have used the wave properties of light to create grainy patterns due to interference, which offers a sensitive probe of both the light and the environment.

The approach will advance optical and quantum sensing technology, enhance the performance of next- generation sensors, and lead to new measuring devices, which may have a variety of uses including in healthcare.

Professor Dholakia worked with Morgan and Dr. Bruce.

Professor Dholakia said that they have scrambled light into a blurry pattern by using either a piece of glass fiber the width of a human hair or a hollow sphere.

The principle of speckle is easy to demonstrate.

If you shine a laser pointer on a rough surface like a painted wall, or a piece of frosted sticky tape, the light from the laser gets scrambled into the grainy speckle pattern.

Normally, we think that scrambling a signal means that we must lose information, but that is not the case here. The exact pattern you see will change if you move the laser. speckle is a good choice for precision measurement because of its sensitivity to change.

The team used these speckle patterns to measure the wavelength of light, which is equivalent to measuring the length of a soccer pitch with an accuracy equivalent to the size of one.

The team used speckle to measure the Refractive index of gases. Changes in the Refractive index of a material can be used to look for subtle changes in the material's properties.

The team reported the measurement of the Refractive index of air to one part in a billion and an order of magnitude improvement over previous speckle-based approaches.

Major implications can be had by small changes in the Refractive index. If the red blood cells in your body have a lowRefractive index, it can be picked up by this sensor. The team hopes to advance this work not only for healthcare but also for field portable sensors that will have various applications, including detection of trace gases or small concentrations of chemicals in liquids.

More information: Morgan Facchin et al, Measurement of Variations in Gas Refractive Index with 10–9 Resolution Using Laser Speckle, ACS Photonics (2022). DOI: 10.1021/acsphotonics.1c01355 Journal information: ACS Photonics Citation: Research team achieves breakthroughs in precision measurement by 'scrambling' laser light (2022, February 22) retrieved 22 February 2022 from https://phys.org/news/2022-02-team-breakthroughs-precision-scrambling-laser.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.