Meta-optics shows the physical process in the attosecond range, a new type of meta-optics from Harvard has been shown to work in experiments at the Graz University of Technology. With it, it is possible to see the smallest structures like nanoparticles or transistors. Developed at Harvard, successfully tested at Graz University of Technology.
The new flexible meta-optics for microscopes with ultra-high resolution and long exposure time have proven suitable for use in laboratory research at the Institute for Experimental Physics from Graz University of Technology. Microscopes with these optics promise completely new research and development methods, especially in semiconductor and solar cell technology. The research team from Graz and Boston are now reporting in the trade magazine “Science” that they are building and experimenting successfully in this new meta-optics laboratory.
The microscope makes it possible for the first time to use ultra violet radiation. Because of their short wavelengths, physical processes can be easily followed at the second level: for example, time records from inside modern transistors or the interaction of molecules and atoms with light. Marcus Ossiander came up with the idea for the new space when he was doing research in Federico Capasso’s group at Harvard University – since January 2023 he is studying ERC Startup Fellowship and FWF START Award Winner at the Institute of Experimental Physics at Graz University of Technology. Connections for Boston and Graz
Attosecond physics uses extreme ultraviolet light. Since this light is very fast and everything in the optical development equipment is not suitable for this light, until now, there is no display system used for this. Marcus Ossiander: “I wonder if the classical principles of optics can be used in the absence of objects and small areas of the basis of optical elements?”
The optics developed at Harvard based on this concept and tested successfully at the Graz University of Technology implemented this principle: the arrangement of small holes and thin silicon film that guides and collects the incident light the second. A notable observation from the research team: these open spaces transmit more energy than is possible due to the area covered by the spaces. This means that the new meta-optics naturally absorb ultraviolet light. Spaces with a diameter of a few nanometers
A smaller and more controlled structure is required for this output. Their production is close to the limit of what is technically possible today. The Harvard team Federico Capasso, a world leader in this field, made the implementation of this technology, after an experimental process of about two years. The proof of operation was made in collaboration with the Graz University of Technology, where Martin Schultze’s group at the Institute for Experimental Physics is working on the generation and application of short-wave ultraviolet light. “It is a great success for the cooperation between Boston and Graz.
Now we want to use it to study microelectronics, nanoparticles, etc.”, Marcus Ossiender explains. Meta-optics consists of a film about 200 nanometers thick, in which a small hole is placed. The entire optic consists of hundreds of millions of holes; There are about ten of these per micrometer in the skin, with a single hole measuring between 20 and 80 nanometers in diameter. For comparison: a human hair is about 60 to 100 micrometers in diameter, a small virus is 15 nanometers in diameter. The diameter of the holes varies and decreases from the center of the skin outwards. Depending on the size of the space, the incident radiation is delayed and thus falls into a small hole.
The laser hits the clouds
Martin Schultze and Hana Hampel of the Institute for Experimental Physics at TU Graz have special expertise in extracting the amount of ultraviolet radiation necessary to measure new optics. “Reliable generation of short-wavelength, high-energy pulses requires precise control of atomically controlled pulses and good optics. For this project, we have developed a light source that generates effective radiation at the wavelength for which this meta-optics is designed,” explains Martin Schultze.
In Graz’s experimental set-up, in which a laser is placed in a focused plane of fine gas, ultra-violet radiation can be generated and channeled into short bursts. With this ultimate light source for attosecond physics, the performance of meta-optics has been demonstrated.
Next step: microscope with meta optics
Creating a microscope that works with these optics is the next step. Marcus Ossiander has also received his ERC start-up grant for this research project in the study of light-emitting nanoparticles – after the Birgitta Schultze-Bernhardt prize in 2020, the second of the high research prizes at the Experimental Institute. in physics from the Graz University of Technology in a short time.
The potential applications for the new research area of attosecond microscopy are numerous. Semiconductor and solar technology will benefit from the ability to travel with fast chargers through space and time for the first time. In modern transistors and optoelectronic circuits, important processes take place in a few nanometers of space in a few seconds. The new meta-optics will make it possible to see these basic elements of our working information technology and to improve them further.
Source: Graz University of Technology
