An optical nanomotor based on light spinning using a circular chain of “pretzel” antennas (Case A) and nano-rods in different directions along the chain (Case B), which allow faster spinning of the light.
A twisted wire composed of optical nanoantennas. In Case A, the antennas have a circular shape – a “pretzel”; and in Case B, the antennas have been shaped into nano-rods, with their direction enabling an additional degree of freedom in controlling the light.
Researchers at the Technion’s Faculty of Mechanical Engineering and the Russell Berrie Nanotechnology Institute have created a new optics by geometric distortion of a wire composed of coupled nanoatennnas.
The researchers developed a new optics based on geometric distortion of the space in the nanoscale. They designed an optical nanoantenna and created a system of such antennas linked to each other. Each antenna, 10 nanometers in size, was built using ion focusing. “I was driving in my car, I looked at the antennas on the cars around me and asked myself the question – what would happen if I distorted the antenna?” explains Prof. Erez Hasman of the Faculty of Mechanical Engineering. “We coupled the nanantennas and produced a straight wire of antennas that behave like one antenna. We then bent the antenna and distorted its space so that the wire looked like a twisted snake. We measured the light exiting from the twisted wire and found that by using a twisted wire, we could shape the light flexibly. We demonstrated this in the lab by having the light spin like a top, which could be used as a nanomotor, and to switch the light in a nanoscale.”
In the second stage, each nanoantenna (nano-rod shape) continued to “run” on the wire, but in its own direction – which enabled the researchers an additional degree of freedom to design a new optics based only on geometric distortion of space and not on the optical differences as in conventional optics, for instance, lenses and prisms. This ability opens up the possibilities for building nanoscale components for information processing, and logic gates that will enable the production of much faster nano-optic chips.
The vision of Prof. Hasman, which appeared in Nature Nanotechnology, described miniature motors, operated only by light, turning DNA and opening it – in order to repair it.
The development was made in the Nanooptics Laboratory at the Technion with the participation of Dr. Vladimir Kleiner and research students, Nir Shitrit, Itay Bretner and Yuri Gorodetski.