With the development of photonic chips and nano-optics, it became necessary to create appropriate microlenses, since their glass “ancestors” are not suitable for this role. And as has already happened more than once, graphene came to the rescue.
A team of researchers at Swinburne University of Technology has developed a one billionth of a meter thick graphene-based microlens, allowing them to capture clear images of bacteria-sized objects. The invention opens up great prospects for improving mobile phones, nanosatellites and computers.
One of the key problems of all optical microscopes is the diffraction limit, that is, the theoretical limit of the resolution of a particular objective. Attempts to solve it using interferometry, holography, lasers and electrons turned out to be ineffective. Success came only as a result of the creation of ultra-thin lenses based on graphene.
The breakthrough was achieved thanks to the efforts of graduate student Xiaorui Zheng, who formed an ultra-thin lens based on graphene oxide, which is 300 times thinner than a sheet of paper and weighs only 1 microgram. It can be used to observe objects 200 nanometers in size, including in the near infrared region.