20 citations · 21 across the 10 of their papers we have counts for
12 papers
Twin Domains in Van der Waals Quaternary Oxides
Dorothée S. Mader, Niels Brumby, Xiaosheng Yang +10
Optical anisotropy is the basis for many intriguing phenomena in van der Waals materials, including hyperbolic polaritons and extreme birefringence. Stacking and twisting van der W…
In-plane vector-field imaging of propagating surface phonon polaritons
Richarda Niemann, Dorothée S. Mader, Gonzalo Alvarez-Pérez +9
Polariton interferometry through optical near-field microscopy has become a powerful tool in nanophotonics, enabling direct spatial access to the propagation characteristics of str…
A two-color dual-oscillator infrared free-electron laser
Wieland Schöllkopf, Sandy Gewinner, Marco De Pas +16
We report on the design and performance of a two-color dual-oscillator infrared free-electron laser (FEL). The mid-infrared (MIR) FEL at the Fritz Haber Institute (FHI FEL) has bee…
Tailoring phonon-driven responses in α-MoO3 through isotopic enrichment
Thiago S. Arnaud, Ryan W. Spangler, Johnathan D. Georgaras +29
The implementation of polaritonic materials into nanoscale devices requires selective tuning of parameters to realize desired spectral or thermal responses. One robust material is…
Non-equilibrium state during proton-deuteron exchange at a liquid-liquid interface
Tillmann Buttersack, Niclas Sven Mueller, Giulia Carini +12
Proton-deuteron exchange is a very fast process, even across macroscopic length scales. Here we directly and quantitatively measure the formation of HDO within the first 100 micros…
Spectral tuning of hyperbolic shear polaritons in monoclinic gallium oxide via isotopic substitution
Giulia Carini, Mohit Pradhan, Elena Gelzinyte +26
Hyperbolic phonon polaritons - hybridized modes arising from the ultrastrong coupling of infrared light to strongly anisotropic lattice vibrations in uniaxial or biaxial polar crys…
Full Crystallographic Imaging of Hexagonal Boron Nitride Monolayers with Phonon-Enhanced Sum-Frequency Microscopy
Niclas S. Mueller, Alexander P. Fellows, Ben John +13
Hexagonal boron nitride (hBN) is an important 2D material for van der Waals heterostructures, single photon emitters, and infrared nanophotonics. The optical characterization of mo…
Surface Phonon Polariton Ellipsometry
Giulia Carini, Richarda Niemann, Niclas Sven Mueller +2
Surface phonon polaritons (SPhPs) have become a key ingredient for infrared nanophotonics, owing to their long lifetimes and the large number of polar dielectric crystals supportin…
Electro-Optic Cavities for In-Situ Measurement of Cavity Fields
Michael S. Spencer, Joanna M. Urban, Maximilian Frenzel +5
Cavity electrodynamics offers a unique avenue for tailoring ground-state material properties, excited-state engineering, and versatile control of quantum matter. Merging these conc…
Sum-Frequency Generation Spectro-Microscopy in the Reststrahlen Band of Wurtzite-type Aluminum Nitride
Dorothée S. Mader, Richarda Niemann, Martin Wolf +2
Nonlinear-optical microscopy and spectroscopy provide detailed spatial and spectroscopic contrast, specifically sensitive to structural symmetry and order. Ferroics, in particular,…
Spectroscopic and Interferometric Sum-Frequency Imaging of Strongly Coupled Phonon Polaritons in SiC Metasurfaces
Richarda Niemann, Niclas S. Mueller, Sören Wasserroth +4
Phonon polaritons enable waveguiding and localization of infrared light with extreme confinement and low losses. The spatial propagation and spectral resonances of such polaritons…
Second-harmonic phonon spectroscopy of -quartz
Christopher J. Winta, Sandy Gewinner, Wieland Schöllkopf +2
We demonstrate midinfrared second-harmonic generation as a highly sensitive phonon spectroscopy technique that we exemplify using -quartz (SiO) as a model system. A midinfra…