Congratulations to Dr. Florian Spreyer. After a successful disputation of his thesis on Hybrid Metamaterials, Mr. Spreyer will leave us. We wish him every success in his further life and career.
When light hits a pinhole with a hole diameter below the wavelength as a plane wave, spherical waves can form behind the pinhole. If now a whole ensemble of holes with well-considered positioning is chosen, the different spherical waves can interfere with each other in any way. The superposition of the transmitted individual waves then results in a new wave front which can, for example, carry image information. Such a construct is called a photon…
Scientists at Paderborn University have now demonstrated, for the very first time, the spatial confinement of a light wave to a point smaller than the wavelength in a ‘topological photonic crystal’.
Who doesn't know the laser sword from the Star Wars movies? But what are lasers and how do they work? What else can you do with them? These were the questions the students of the MINT-EC-Camp: Laser Physics explored during their visit to the Department of Physics.
Photo (Jamie Kidston, ANU): With a Marie Skłodowska Curie Fellowship from the EU, Dr. Sergey Kruk from the Australian National University is conducting research at the University of Paderborn in the field of nonlinear nano-optics.
Professor Thomas Zentgraf from the Physics Department has now been selected as the second Paderborn physicist as a new Fellow of the Max Planck School for Photonics.
Congratulations to Dr. Christian Schlickriede. After a successful disputation of his thesis on Nonlinear Metalenses, Mr. Schlickriede will leave us. We wish him every success in his further life and career.
Nonlinear plasmonic metasurface for color holography. Rotation symmetric gold nano antennas are used to encode a holographic image based on the Pancharatnam–Berry phase. The position of the meta-atoms can be randomly distributed in a square lattice, while the rotation of each antenna is significant for the image encryption. The schematic illustration shows a nonlinear plasmonic metasurface, which can carry holographic information, for instance, a colored tree and house. If the metasurface is illuminated at its resonance frequency ω, the image is generated at frequencies 2ω and 3ω in Fourier space.
In our recent publication entitled ‘Nonlinear Bicolor Holography Using Plasmonic Metasurfaces’ published in ACS Photonics, we show that two types of nanoparticle scatterers combined in one geometric metasurface can form a nonlinear colored hologram.
In a joint project between the group of Professor Thomas Zentgraf at the University of Paderborn and Professor Junsuk Rho at the Pohang University of Science and Technology in Korea, both groups plan to develop so-called multifunctional metasurfaces.
Photo (Uni Paderborn, Department of Physics): Front v. l .: Leonard Giller and Merle Hüllmann took part in lectures given by physicist Prof. Dr. Thomas Zentgraf (center back). They got to know, among other things, the so-called Pohl wheel and bicycle tires to demonstrate physical effects.
Since February 2020, Dr. Sergey Kruk from the Australian National University is workingin the group of Prof. Thomas Zentgraf at the University of Paderborn in the field of non-reciprocal nano-optics.
During a visit with our project partner Prof. Huang at the Beijing Institute of Technology in Beijing (China) we discussed the properties of nonlinear metasurfaces during a seminar. The exchange is financially supported by the DFG and the NSFC.