April 20, 2024

Electrically Switchable Nanoantennas Developed for Holographic Video Technology

By University of Stuttgart
November 20, 2021

Scientists at the University of Stuttgart in Germany have actually now introduced a completely brand-new method to recognize such vibrant holographic displays, based on electrically switchable plasmonic nanoantennas made from conductive metallic polymers. In partnership with cleanroom head Monika Ubl, Karst and Hentschel established a procedure to nanostructure the metal polymers using a combination of electron beam lithography and etching, thereby producing the plasmonic nanoantennas. Left: Image displaying the plasmonic polymer nanoantenna, changed into the dielectric (glassy) state.: Image showing the plasmonic polymer nanoantenna, switched into the metal state. The optical residential or commercial properties of the polymer nanoantennas have to be shifted into the noticeable wavelength variety, which requires cooperations with chemists and product researchers.

Scientists establish electrically switchable nanoantennas as basis for holographic video innovation. Credit: University of Stuttgart/PI4, Julian Karst
Real-Life Feeling at Online Video Conferences
Scientists at the University of Stuttgart in Germany have now introduced an entirely brand-new approach to recognize such dynamic holographic screens, based on electrically switchable plasmonic nanoantennas made from conductive metal polymers. This crucial component offers the missing innovation to enable holographic displays at video rate, which would enable virtual conferences with a “real-life” feeling.
Virtual conference in the future: The conference member on the right is using VR/AR goggles, which show a hologram of the woman on the. Credit: University of Stuttgart/PI4, Julian Karst
Dynamic holograms switchable at video rates utilizing information from a high-speed web connection are not possible up until now. Previously, the limiting factor was the display screen resolution. Holographic images require a resolution of 50,000 dpi (pixels per inch) which is 100x more than the best smartphone screens.
Researchers at the University of Stuttgart have prospered in breaking this fundamental barrier. In an interdisciplinary partnership between Physics and Chemistry, they established the idea to utilize electrically switchable plasmonic nanoantennas with dimensions of just a few hundred nanometers and made from conductive polymers.

Scanning electron microscopic lense (SEM) image of the metal polymer metasurface that can be utilized for electrical nanoantenna switching. Credit: University of Stuttgart/PI4, Julian Karst
Conductive functional polymers as appropriate switchable product.

Karst produced a simple hologram metasurface from the nanoantennas that might deflect an infrared laser beam 10 degrees onto one side by using a voltage. Currently, he is working on making this deflection offered for lots of angles for applications in LIDAR devices in self-governing automobiles, of keen interest to the automobile industry. Furthermore, Karst developed a hologram that behaves like an optical lens, which can be switched on and off by just applying ± 1 Volt. This innovation is important for future smartphone cams or optical sensors that could be zoomed from broad angle to telephoto by switching the used voltage. Presently, approximately 4 lenses are needed for this functionality.
In the future, Prof. Harald Giessen and his group goal to resolve every single pixel separately, to dynamically change the holograms at will at video rates. Likewise, the optical homes of the polymer nanoantennas need to be moved into the noticeable wavelength range, which needs partnerships with chemists and material researchers. Together with engineers, incorporated and dynamically switchable optical display screens and the first moving holograms might be incorporated into AR/VR goggles and ultimately onto smartphone screens and even televisions..
Taking Moores law for screen technology, this advance by about a factor of 100 might happen commercially around the year 2035.
Reference: “Electrically switchable metallic polymer nanoantennas” by Julian Karst, Moritz Floess, Monika Ubl, Carsten Dingler, Claudia Malacrida, Tobias Steinle, Sabine Ludwigs, Mario Hentschel and Harald Giessen, 28 October 2021, Science.DOI: 10.1126/ science.abj3433.

Their components, or nanoantennas, consisted of metals such as gold or aluminum that might not be switched like common liquid crystal materials. After browsing for several years for the best product, PhD student Julian Karst and nanophotonics specialist Dr. Mario Hentschel from the group of Prof. Harald Giessen, together with polymer chemist Prof. Sabine Ludwigs and her team, identified electrically conducting polymers as possible prospects for switchable plasmonics.
In cooperation with cleanroom head Monika Ubl, Karst and Hentschel established a process to nanostructure the metallic polymers utilizing a combination of electron beam lithography and etching, thus creating the plasmonic nanoantennas. The team showed that the optical appearance of the nanoantennas might be changed between that of a shiny metal and a transparent product by using a voltage between minus and plus one volt. Regardless of being only a couple of 10s of nanometers thick and less than 400 nanometers in size, the nanoantennas do the exact same job as the much larger and thicker liquid crystals used in existing advanced innovation.
Left: Image displaying the plasmonic polymer nanoantenna, switched into the dielectric (glassy) state.: Image showing the plasmonic polymer nanoantenna, switched into the metal state. Credit: University of Stuttgart/PI4, Julian Karst.