Superlens Tuning by Ferroelectrics (STuFe)

• Applicant: Dr. Susanne Kehr
• Subject Area: Experimental Condensed Matter Physics ; Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 282590387

Metamaterial-based superlensing constitutes a fascinating and lucrative research topic combining clever physical concepts of negative optical refraction with top-modern material science approaches. We propose here to fabricate, evaluate and model superlenses based on layered ferroelectric materials in order to achieve a low-loss and spectrally tunable super-resolution of one-fiftieth of the wavelength. We thus combine in this project our expertise in the field of ferroelectric metamaterials and near-field microscopy, in order to achieve infrared (IR) tunability for both microscopic and spectroscopic applications. In particular, near- to far-IR wavelengths are in our focus targeting for applications at fingerprint wavelengths of biological and organic single molecules (remote imaging), down to THz superlensing exploring top-modern materials such as layered 2D-conductors.In particular we are refining superlenses towards spectral tunability and functionality in order to increase their spectral bandwidth. Ferroelectric materials are ideally suited for this purpose due to their tensorial piezoelectric, electrooptic or pyroelectric properties. Hence, using external stimuli will elegantly allow us for instance to precisely adjust material resonances to molecular fluorescence emission signals, thus providing an efficient on/off switching of our superlenses. To address this tunability in our experiment we profit from our earlier work where we combined nanoscopic superlens imaging through IR-scattering near-field optical microscopy, with the broadband laser source of a free-electron laser at the Helmholtz Center Dresden-Rossendorf (HZDR), Germany, covering the 4 to 250 micrometer wavelength range. Furthermore, our experimental superlens approach will well be backed-up by a profound theoretical understanding. We will evaluate their optical response and tune it via external electric fields with a possible extension to further external stimuli such as magnetic fields, mechanical strain, temperature gradients and/or UV illumination.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr. Lukas M. Eng