Microscopy at the tip of a hair-thin optical fibre
Researchers at the 成人大片, as part of an international team, have developed an approach that makes advanced聽microscopy possible through an optical fibre thinner than a human hair.
鈥淩ecent advances in optics have made it possible to controllably deliver light through extremely thin optical fibres, but delivering聽more complicated light patterns that are needed to perform advanced microscopy has eluded researchers until now,鈥 said Dr
Ralf Mouthaan from the 成人大片鈥檚 Centre of Light for Life, who undertook the project.
鈥淲ith a footprint far smaller than any other fibre imaging device, this will enable microscope images to be collected from聽previously inaccessible parts of the human body, while minimising associated tissue damage.
鈥淟ight transmitted through an optical fibre is distorted as it propagates. As the size of the fibre approaches the width of a human聽hair, this distortion results in an apparently random granular pattern.
鈥淣ew approaches have begun to correct for this distortion, allowing ultra-thin footprint devices to penetrate previously聽inaccessible parts of the body.
鈥淗owever, these approaches result in imperfect light beams, making them unsuitable for super-resolution or wide-field聽microscopy.
鈥淧erforming advanced microscopy in a hair-thin fibre will reveal a wealth of additional information.鈥
The new approach will benefit advanced microscopy techniques such as light sheet microscopy, in which a volumetric image of聽the sample is built up by imaging one plane at a time, or stimulated emission-depletion (STED) microscopy, which allows聽incredibly small structures a billionth of a metre in diameter to be imaged.
This project was undertaken by Dr Ralf Mouthaan and is the result of a strong international collaboration with Dr Peter聽Christopher and Dr George Gordon at the University of Nottingham, UK, as well as Professor Tim Wilkinson and Professor聽Tijmen Euser at the University of Cambridge, UK. Professor Kishan Dholakia leads the Adelaide team as the Director of the聽Centre of Light for Life.
The team has now demonstrated that it is possible to pre-shape light so that they can generate any desired optical pattern,聽even after distortion.
The approach described in their paper published in , provides unprecedented control over the聽amplitude, phase and polarisation of the beam at the output of the fibre. They demonstrate the projection of exotic patterns of聽light such as Bessel beams, Airy beams and Laguerre-Gaussian beams, each of which has unique properties that underpin聽modern microscopy techniques.
鈥淲hile many advanced microscopes can occupy an entire lab, this approach is a major step for microscopes to be miniaturised聽to the point that microscope images can be taken inside the human body,鈥 said Dr Mouthaan.
鈥淭here is almost no limit to what can be projected through the fibre. For example, a letter such as the Greek alpha can also be formed.鈥
The team in Adelaide will now move to demonstrating the first proof of concept 鈥渆ndomicroscopes鈥, while members of the team聽at the University of Nottingham work to build an endoscope ready for clinical use.
This work was funded by the Australian Research Council and the UK鈥檚 Engineering and Physical Sciences Research Council.
Media Contacts:
Dr Ralf Mouthaan, School of Biological Sciences, 成人大片. Mobile: +61 (0)474 160 921, Email:聽ralf.mouthaan@adelaide.edu.au,
Crispin Savage, Manager, News and Media, The 成人大片. Mobile: +61 (0)481 912 465, Email:聽crispin.savage@adelaide.edu.au