2023-10-19 10:48:24
Scientists used a new superlensing technique to view an object just 0.15 millimeters wide using a virtual post-observation technique. – UNIVERSITY OF SYDNEY
MADRID, 19 Oct. (EUROPA PRESS) –
Physicists from the University of Sydney have shown how to push the limits of microscopy, dispensing with the traditional super-lens optical method.
There are physical limits to the precision with which we can examine an object using lenses. This is known as diffraction limit and is determined by the fact that light manifests as a wave. This means that a focused image can never be smaller than half the wavelength of the light used to observe an object.
All attempts to break this limit with “super lenses” have run into the obstacle of extreme visual loss, which causes the lenses to become opaque. Now, the Sydney team have managed to exceed the diffraction limit by a factor of almost four times. Publish results in Nature Communications.
Lead author of the research, Dr Alessandro Tuniz from the School of Physics and the Nano Institute at the University of Sydney, said it’s a statement: “We have now developed a practical way to implement the superlens, without a superlens. To do this, we place our light probe away from the object and collected high- and low-resolution information. By measuring further away, the probe does not interfere with high-resolution data, a feature of previous methods.”
Previous attempts have attempted to make superlenses using novel materials. However, most materials absorb too much light for the super lens to be useful.
Dr Tuniz said: “We overcame this by performing the superlensing operation as a post-processing step in a computer, after the measurement itself. “This produces a ‘truthful’ image of the object through the selective amplification of evanescent light waves.”
Co-author Associate Professor Boris Kuhlmey, also from the School of Physics and Sydney Nano, said: “Our method could be applied to determine the moisture content in leaves at higher resolution, or be useful in advanced microfabrication techniques, such as non-destructive evaluation”. of the integrity of the microchip. And the method could even be used to reveal hidden layers in works of art, perhaps proving useful in discovering art forgeries or hidden works.”
Typically, superlens attempts have attempted to focus closely on high-resolution information. This is because this useful data decays exponentially with distance and is quickly overtaken by low-resolution data, which does not decay as quickly. However, bringing the probe so close to an object distorts the image.
“By moving our probe away we can maintain the integrity of the high-resolution information and use a post-observation technique to filter out the low-resolution data,” Associate Professor Kuhlmey said.
The research was carried out using light at a frequency of terahertz at a millimeter wavelength, in the region of the spectrum between visible and microwave.
Associate Professor Kuhlmey said: “It is very difficult to work with this frequency range, but very interesting, because in this range we could obtain important information about biological samples, such as protein structure, hydration dynamics or for use in cancer imaging.”
Dr Tuniz said: “This technique is a first step in allowing high resolution images while staying a safe distance from the object without distorting what is seen. Our technique could be used in other frequency ranges. We hope that anyone who performs high-resolution imaging with optical microscopy will find this technique of interest.”
#Physicists #push #microscopes #limits