Abstract-Terahertz three-dimensional monitoring of nanoparticle-assisted laser tissue soldering

Junliang Dong, Holger Breitenborn, Riccardo Piccoli, Lucas V. Besteiro, Pei You, Diego Caraffini, Zhiming M. Wang, Alexander O. Govorov, Rafik Naccache, Fiorenzo Vetrone, Luca Razzari, and Roberto Morandotti

Schematic showing the range of simultaneous photothermal reactions during nanoparticle-assisted laser tissue soldering.

https://www.osapublishing.org/boe/abstract.cfm?uri=boe-11-4-2254

In view of minimally-invasive clinical interventions, laser tissue soldering assisted by plasmonic nanoparticles is emerging as an appealing concept in surgical medicine, holding the promise of surgeries without sutures. Rigorous monitoring of the plasmonically-heated solder and the underlying tissue is crucial for optimizing the soldering bonding strength and minimizing the photothermal damage. To this end, we propose a non-invasive, non-contact, and non-ionizing modality for monitoring nanoparticle-assisted laser-tissue interaction and visualizing the localized photothermal damage, by taking advantage of the unique sensitivity of terahertz radiation to the hydration level of biological tissue. We demonstrate that terahertz radiation can be employed as a versatile tool to reveal the thermally-affected evolution in tissue, and to quantitatively characterize the photothermal damage induced by nanoparticle-assisted laser tissue soldering in three dimensions. Our approach can be easily extended and applied across a broad range of clinical applications involving laser-tissue interaction, such as laser ablation and photothermal therapies.

© 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Abstract-Reshaping the phonon energy landscape of nanocrystals inside a terahertz plasmonic nanocavity

Xin Jin, Andrea Cerea, Gabriele C. Messina, Andrea Rovere, Riccardo Piccoli, Francesco De Donato, Francisco Palazon, Andrea Perucchi, Paola Di Pietro, Roberto Morandotti, Stefano Lupi, Francesco De Angelis, Mirko Prato, Andrea Toma,  Luca Razzari

https://www.nature.com/articles/s41467-018-03120-3

Phonons (quanta of collective vibrations) are a major source of energy dissipation and drive some of the most relevant properties of materials. In nanotechnology, phonons severely affect light emission and charge transport of nanodevices. While the phonon response is conventionally considered an inherent property of a nanomaterial, here we show that the dipole-active phonon resonance of semiconducting (CdS) nanocrystals can be drastically reshaped inside a terahertz plasmonic nanocavity, via the phonon strong coupling with the cavity vacuum electric field. Such quantum zero-point field can indeed reach extreme values in a plasmonic nanocavity, thanks to a mode volume well below λ3/107. Through Raman measurements, we find that the nanocrystals within a nanocavity exhibit two new “hybridized” phonon peaks, whose spectral separation increases with the number of nanocrystals. Our findings open exciting perspectives for engineering the optical phonon response of functional nanomaterials and for implementing a novel platform for nanoscale quantum optomechanics

Abstract-Generation of high-field terahertz pulses in an HMQ-TMS organic crystal pumped by an ytterbium laser at 1030 nm

Andrea Rovere, Young-Gyun Jeong, Riccardo Piccoli, Seung-Heon Lee, Seung-Chul Lee, O-Pil Kwon, Mojca Jazbinsek, Roberto Morandotti, and Luca Razzari

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-26-3-2509

We present the generation of high-peak-electric-field terahertz pulses via collinear optical rectification in a 2-(4-hydroxy-3-methoxystyryl)-1-methilquinolinium-2,4,6-trimethylbenzenesulfonate (HMQ-TMS) organic crystal. The crystal is pumped by an amplified ytterbium laser system, emitting 170-fs-long pulses centered at 1030 nm. A terahertz peak electric field greater than 200 kV/cm is obtained for 420 µJ of optical pump energy, with an energy conversion efficiency of 0.26% - about two orders of magnitude higher than in common inorganic crystals collinearly pumped by amplified femtosecond lasers. An open-aperture Z-scan measurement performed on an n-doped InGaAs thin film using such terahertz source shows a nonlinear increase in the terahertz transmission of about 2.2 times. Our findings demonstrate the potential of this terahertz generation scheme, based on ytterbium laser technology, as a simple and efficient alternative to the existing intense table-top terahertz sources. In particular, we show that it can be readily used to explore nonlinear effects at terahertz frequencies.

© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Abstract-Multi-dimensional Imaging in the Terahertz Regime for Theranostic Applications

Holger Breitenborn, Rafik Naccache, Anna Mazhorova, Matteo Clerici, Riccardo Piccoli, Larousse K. Khorashad, Alexander O. Govorov, Luca Razzari, Fiorenzo Vetrone, and Roberto Morandotti

https://www.osapublishing.org/abstract.cfm?uri=cleo_at-2017-ATu3A.6&origin=search

We demonstrate a novel terahertz radiation-based joint thermal-hyperspectral imaging method for theranostic applications. Hyperspectral imaging of a drug formulation was realized in the stratum granulosum of skin, in the presence of plasmonically heated gold nanoparticles.