Ultrafast Nonlinear Dynamics of Indium Tin Oxide Nanocrystals Probed via Fieldoscopy

Herbst A, Srivastava A, Scheffter K, Jun S, Gommel S, Rebecchi L, Kuriyil S, Rubino A, Petrini N, Kriegel I, Fattahi H (2025)

Publication Type: Journal article

Publication year: 2025

Journal

Advanced Science Wiley Open Access

DOI: 10.1002/advs.202516818

Abstract

Scalable, high-speed, small-footprint photonic switching platforms are essential for advancing optical communication. An effective optical switch must operate at high duty cycles with fast recovery times, while maintaining substantial modulation depth and full reversibility. Colloidal nanocrystals, such as indium tin oxide (ITO), offer a scalable platform to meet these requirements. In this work, the transmission of ITO nanocrystals near their epsilon-near-zero wavelength is modulated by two-cycle optical pulses at a repetition rate of one megahertz. The modulator exhibits a broad bandwidth spanning from 2 to 2.5 µm. Sensitive fieldoscopy measurements resolve the transient electric-field response of the ITO for the first time, showing that the modulation remains reversible for excitation fluences up to 1.2 mJ cm−2 with a modulation depth of 10%, and becomes fully irreversible beyond 3.3 mJ cm−2, while reaching modulation depth of up to 20%. Field sampling further indicates that at higher excitation fluences, the relative contribution from the first cycle of the optical pulses is reduced. These findings are crucial for the development of all-optical switching, telecommunications, and sensing technologies capable of operating at terahertz switching frequencies.

Authors with CRIS profile

Andreas Herbst
Kilian Scheffter
Soyeon Jun

Involved external institutions

Max-Planck-Institut für die Physik des Lichts (MPL) / Max Planck Institute for the Science of Light DE Germany (DE) Politecnico di Torino IT Italy (IT)

How to cite

APA:

Herbst, A., Srivastava, A., Scheffter, K., Jun, S., Gommel, S., Rebecchi, L.,... Fattahi, H. (2025). Ultrafast Nonlinear Dynamics of Indium Tin Oxide Nanocrystals Probed via Fieldoscopy. Advanced Science. https://doi.org/10.1002/advs.202516818

MLA:

Herbst, Andreas, et al. "Ultrafast Nonlinear Dynamics of Indium Tin Oxide Nanocrystals Probed via Fieldoscopy." Advanced Science (2025).

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