Abstract-Quantitative terahertz emission nanoscopy with multiresonant near-field probes

 

Fabian Mooshammer, Markus Plankl, Thomas Siday, Martin Zizlsperger, Fabian Sandner, Rocco Vitalone, Ran Jing, Markus A. Huber, D. N. Basov, and Rupert Huber

https://www.osapublishing.org/viewmedia.cfm?r=1&rwjcode=ol&uri=ol-46-15-3572&seq=0

By sampling terahertz waveforms emitted from InAs surfaces, we reveal how the entire, realistic geometry of typical near-field probes drastically impacts the broadband electromagnetic fields. In the time domain, these modifications manifest as a shift in the carrier-envelope phase and emergence of a replica pulse with a time delay dictated by the length of the cantilever. This interpretation is fully corroborated by quantitative simulations of terahertz emission nanoscopy based on the finite element method. Our approach provides a solid theoretical framework for quantitative nanospectroscopy and sets the stage for a reliable description of subcycle, near-field microscopy at terahertz frequencies.

© 2021 Optical Society of America

Abstract-Ultrafast field-resolved multi-THz spectroscopy on the sub-nanoparticle scale

Tyler L. Cocker; Max Eisele; Markus A. Huber; Markus Plankl; Leonardo Viti; Daniele Ercolani; Lucia Sorba; Miriam S. Vitiello; Rupert Huber

http://spie.org/Publications/Proceedings/Paper/10.1117/12.2188562

Terahertz spectroscopy plays a key role in understanding ultrafast carrier dynamics in nanomaterials. Diffraction, however, limits time-resolved terahertz spectroscopy to ensemble measurements. By combining time-resolved terahertz spectroscopy in the multi-terahertz range with scattering-type near-field scanning optical microscopy, we show that we can directly trace ultrafast local carrier dynamics in single nanoparticles with sub-cycle temporal resolution (10 fs). Our microscope provides both 10 nm lateral resolution and tomographic sensitivity, allowing us to observe the ultrafast build-up of a local surface depletion layer in an InAs nanowire.