The various circuits used for optical readings all have the same principle: the measured quantity must leave a trace for the system’s optical response. Traces can be in the form of transmission, reflection or absorption.
The stronger this effect, the more the system responds.
Even though this works well at the macroscopic level, measuring small microscopic sizes that cause dim reactions is a challenging task. Researchers have developed techniques to overcome this difficulty and increase the sensitivity of their devices.
Some of these techniques, which are based on complex concepts and quantum-optical implementations, actually prove useful, for example when considering gravitational waves in the LIGO project. Others based on light traps in small boxes, called optical resonators, have found relatively large micro particles and biological components.
However, the ability to detect small nanoparticles and the possibility of a single molecule remains challenging. Recent studies have focused on specific types of photoreceptors, microning or micrototorion resonators that increase the interaction between light and molecules to be detected.
However, the sensitivity of this device is limited by their basic physics. Physicists and engineers from Michigan University of Technology, Pennsylvania State University, and the University of Central Florida offer new types of sensors in their article, Sensing with Exclusive Surfaces to Combine Sensitivity to Sustainability, published in Physical Review Letters. They are based on a new concept of extraordinary surface: a surface consisting of extraordinary points.
Extraordinary points for detection that are very sensitive To understand the meaning of extraordinary points, consider an imaginary violin with only two strings. In principle, such violins can only produce two different tones – a situation that is compatible with conventional optical resonators.
If the vibrations of one string can change the vibrations of the other strings so that aural and elastic variations only produce sound and collective movement, the system has an extraordinary point.
The physical system, which has extraordinary points, is very fragile. In other words, a little confusion will change his behavior drastically. This feature makes the system very sensitive to small signals.
Apart from this promise, the increase in sensor sensitivity based on extraordinary points is Achilles weakness: this device is very sensitive to unavoidable manufacturing defects and unwanted environmental changes, said Rami El-Ghanaini, a physics professor, adding that sensitivity .
In previous experimental demonstrations, setting cunning tricks was needed. Our current proposal eliminates most of these problems by introducing new systems that have the same sensitivity as those reported in previous studies, and at the same time are strong against most unnecessary experimental uncertainties,” said Chi Chung, lead author of the report. and a PhD student is currently working on his doctoral thesis at Michigan technology.