2023-10-20 19:15:25
Since Antonie van Leeuwenhoek discovered the world of bacteria through a microscope at the end of the 17th century, humans have always tried to look deeper into the world of the smallest. However, there are physical limits to the precision with which we can examine an object using traditional optical methods. This is known as the “diffraction limit” and is determined by the fact that light appears as a wave. This means that a focused image can never be smaller than half the wavelength of the light used to observe the object.
Previous attempts to break this limit with “superlenses” were based on making them from innovative materials. However, typically these materials absorb too much light for the superlens to be useful.
These superlenses suffer considerable optical loss, to the point that in many of the observations attempted with them, they can be considered opaque for practical purposes,
Now, physicists Alessandro Tuniz and Boris T. Kuhlmey, both from the University of Sydney in Australia, have demonstrated a new strategy for seeing through a superlens with minimal losses, breaking the diffraction limit by a factor of almost four times. . .
The key to its success was, paradoxically, completely eliminating the superlens itself. The work that the superlens would do is done by a subsequent data processing step in a computer, after the measurement.
The object observed in the tests, “THZ” (the acronym for terahertz, the band of light frequencies used), is shown as seen with the initial optical measurement (top right), after a normal lens application (bottom left) and after applying the superlens effect without using a real superlens (bottom right). (Images: The University of Sydney)
On the other hand, the light probe, which collects high and low resolution data, is located far from the object to be observed, thus preventing it from interfering with the high resolution data as occurs with other systems.
The end result is the production of a “truthful” image of the object through the selective amplification of evanescent or disappearing light waves.
What has been achieved by these physicists will improve the resolution of optical microscopy, making it possible to obtain optical images that would have been impossible before, which will have a very positive impact on fields such as oncological diagnoses, obtaining medical images in general, police forensic investigations and archaeology.
Tuniz and Kuhlmey present the technical details of their new system in the academic journal Nature Communications, under the title “Subwavelength terahertz imaging via virtual superlensing in the radiating near field.” (Source: NCYT from Amazings)
#optical #microscopes #limits