Universität Stuttgart
Permanent URI for this communityhttps://elib.uni-stuttgart.de/handle/11682/1
Browse
4 results
Search Results
Item Open Access Focused surface plasmon polaritons coherently couple to electronic states in above-threshold electron emission(2023) Dreher, Pascal; Janoschka, David; Frank, Bettina; Giessen, Harald; Meyer zu Heringdorf, Frank-JoachimWhen an intense light field strongly interacts with the band structure of a solid, the formation of hybrid light-matter quantum states becomes possible. Examples of such Floquet-Bloch states have been reported, but engineering of the band structure using Floquet states can suffer from dissipation and decoherence. Sustaining the necessary quantum coherence of the light-matter interactions requires robust electronic states in combination with strong fields of suitable polarization and frequency. Here, we explore the quantum coherent coupling of nano-focused surface plasmon polaritons (SPP) to distinct electronic states in the band structure of a solid. We observe above-threshold electron emission from the Au(111) Shockley surface state by the absorption of up to seven SPP quanta. Using time-resolved photoelectron spectroscopy the coherence of the interaction of the SPPs with the surface state during electron emission is investigated and the process is shown to be similar to light-driven above threshold electron emission. Ultimately, our work could render SPP-based Floquet engineering in nano-optical systems feasible.Item Open Access Micro- and nanofabrication of dynamic hydrogels with multichannel information(2023) Zhang, Mingchao; Lee, Yohan; Zheng, Zhiqiang; Khan, Muhammad Turab Ali; Lyu, Xianglong; Byun, Junghwan; Giessen, Harald; Sitti, MetinCreating micro/nanostructures containing multi-channel information within responsive hydrogels presents exciting opportunities for dynamically changing functionalities. However, fabricating these structures is immensely challenging due to the soft and dynamic nature of hydrogels, often resulting in unintended structural deformations or destruction. Here, we demonstrate that dehydrated hydrogels, treated by a programmable femtosecond laser, can allow for a robust fabrication of micro/nanostructures. The dehydration enhances the rigidity of the hydrogels and temporarily locks the dynamic behaviours, significantly promoting their structural integrity during the fabrication process. By utilizing versatile dosage domains of the femtosecond laser, we create micro-grooves on the hydrogel surface through the use of a high-dosage mode, while also altering the fluorescent intensity within the rest of the non-ablated areas via a low-dosage laser. In this way, we rationally design a pixel unit containing three-channel information: structural color, polarization state, and fluorescent intensity, and encode three complex image information sets into these channels. Distinct images at the same location were simultaneously printed onto the hydrogel, which can be observed individually under different imaging modes without cross-talk. Notably, the recovered dynamic responsiveness of the hydrogel enables a multi-information-encoded surface that can sequentially display different information as the temperature changes.Item Open Access Positional accuracy of 3D printed quantum emitter fiber couplers(2024) Weber, Ksenia; Thiele, Simon; Hentschel, Mario; Herkommer, Alois; Giessen, HaraldPrecise positioning of optical elements plays a key role in the performance of optical systems. While additive manufacturing techniques such as 3D printing enable the creation of entire complex micro‐objectives in one step, thus rendering lens alignment unnecessary, certain applications require precise positional alignment of the printing process with respect to the substrate. For example, in order to efficiently couple quantum emitters to single‐mode fibers, which is a crucial step in the development of real world quantum networks, precise alignment between the emitter, the coupling optics, and the single‐mode fiber is of utmost importance. In this work, the positioning accuracy of a Photonics Professional GT (Nanoscribe GmbH) 3D printing machine is evaluated by using the integrated piezo stage to align to gold markers that is manufactured via e‐beam lithography. By running a statistical analysis of 38 printing cycles, a mean positional error of only 80 nm is determined. Additionally, an entire system is 3D printed that can couple quantum emitters to optical single‐mode fibers. Examining the focal spot of the 3D printed micro‐optics, a positional accuracy of ≈ 1 µm in all three dimensions is found, as well as excellent quality of the focal spot.Item Open Access Terahertz magnetic response of plasmonic metasurface resonators : origin and orientation dependence(2024) Tesi, Lorenzo; Hrtoň, Martin; Bloos, Dominik; Hentschel, Mario; Šikola, Tomáš; Slageren, Joris vanThe increasing miniaturization of everyday devices necessitates advancements in surface-sensitive techniques to access phenomena more effectively. Magnetic resonance methods, such as nuclear or electron paramagnetic resonance, play a crucial role due to their unique analytical capabilities. Recently, the development of a novel plasmonic metasurface resonator aimed at boosting the THz electron magnetic response in 2D materials resulted in a significant magnetic field enhancement, confirmed by both numerical simulations and experimental data. Yet, the mechanisms driving this resonance were not explored in detail. In this study, we elucidate these mechanisms using two semi-analytical models: one addressing the resonant behaviour and the other examining the orientation-dependent response, considering the anisotropy of the antennas and experimental framework. Our findings contribute to advancing magnetic spectroscopic techniques, broadening their applicability to 2D systems.