Title:	NIR-to-NIR Imaging: Extended Excitation Up to 2.2 μm Using Harmonic Nanoparticles with a Tunable hIGh EneRgy (TIGER) Widefield Microscope
Authors:	Vittadello, Laura Klenen, Jan Koempe, Karsten Kocsor, Laura Szaller, Zsuzsanna Imlau, Mirco
ORCID of the author:	https://orcid.org/0000-0003-2824-2127 https://orcid.org/0000-0001-5654-5737 https://orcid.org/0000-0001-8023-0946 https://orcid.org/0000-0002-5343-5636 https://orcid.org/0000-0003-3284-784X
Abstract:	Near-infrared (NIR) marker-based imaging is of growing importance for deep tissue imaging and is based on a considerable reduction of optical losses at large wavelengths. We aim to extend the range of NIR excitation wavelengths particularly to values beyond 1.6 μm in order to profit from the low loss biological windows NIR-III and NIR-IV. We address this task by studying NIR-excitation to NIR-emission conversion and imaging in the range of 1200 up to 2400 nm at the example of harmonic Mg-doped lithium niobate nanoparticles (i) using a nonlinear diffuse femtosecond-pulse reflectometer and (ii) a Tunable hIGh EneRgy (TIGER) widefield microscope. We successfully demonstrate the existence of appropriate excitation/emission configurations in this spectral region taking harmonic generation into account. Moreover, NIR-imaging using the most striking configurations NIR-III to NIR-I, based on second harmonic generation (SHG), and NIR-IV to NIR-I, based on third harmonic generation (THG), is demonstrated with excitation wavelengths from 1.6–1.8 μm and from 2.1–2.2 μm, respectively. The advantages of the approach and the potential to additionally extend the emission range up to 2400 nm, making use of sum frequency generation (SFG) and difference frequency generation (DFG), are discussed.
Citations:	Vittadello, L.; Klenen, J.; Koempe, K.; Kocsor, L.; Szaller, Z.; Imlau, M.: NIR-to-NIR Imaging: Extended Excitation Up to 2.2 μm Using Harmonic Nanoparticles with a Tunable hIGh EneRgy (TIGER) Widefield Microscope. Nanomaterials 2021, 11, 3193.
URL:	https://doi.org/10.48693/66 https://osnadocs.ub.uni-osnabrueck.de/handle/ds-202202116347
Subject Keywords:	biological windows; NIR-III; NIR-IV; NIR imaging; nonlinear microscopy; nonlinear photonics; deep tissue imaging harmonic nanoparticles; second harmonic generation
Issue Date:	25-Nov-2021
License name:	Attribution 4.0 International
License url:	http://creativecommons.org/licenses/by/4.0/
Type of publication:	Einzelbeitrag in einer wissenschaftlichen Zeitschrift [article]
Appears in Collections:	FB06 - Hochschulschriften Open-Access-Publikationsfonds

This item is licensed under a Creative Commons License