Intrinsic optical bistability and temperature sensing in the Laser-Induced Anti-Stokes broadband white light emission

Year: 2026

Authors: Ramos T.J.S.

Autors Affiliation: European Lab Non Linear Spect LENS, Via Nello Carrara 1, I-50019 Sesto Fiorentino, Italy; CNR, Ist Nazl Ott, Largo Fermi 6, I-50125 Florence, Italy.

Abstract: In this work, we provide a detailed investigation into the underlying mechanisms of laser-induced white light emission (LIWE) and examine the effects of particle size and bulk properties on the optical features of lanthanide sesquioxides. The upconversion emission colour is tunable by changes in sample packing density, laser diode intensity and continuous excitation wavelength at 808 or 980 nm up to 11 kW cm- 2. The results demonstrate that the slope for the linear fit for Log ILIWE vs Log PD should not be interpreted as the number of photons in the LIWE process. The temporal dynamics and photoconductivity analysis indicate that multiphoton ionisation and avalanche processes are not involved in LIWE generation. The minor resistance oscillations (within one order of magnitude) over a timescale of seconds, along with photocurrent intensities in the nA, can be attributed to a light-to-heat mechanism induced by laser excitation. The single emitters reported here present intrinsic optical bistability coupled to temperature sensing in a wide range, 972-2542 K, with a high resolution of 0.2 K. The photophysical analysis indicates that there are two optical bistable emissions at low/high laser power densities.

Journal/Review: JOURNAL OF LUMINESCENCE

Volume: 290      Pages from: 121655-1  to: 121655-11

More Information: The author sincerely thanks the Photonic Hybrids and Nanomaterials group (Phantom-G) at the University of Aveiro for providing the necessary infrastructure for the synthesis and characterisation of the analysed materials. Appreciation is also extended to the Institute of Low Temperature and Structure Research (INTiBS) for its support with the photoconductivity investigations, and to Dr. Pawe l G l uchowski for his contribution to the preparation of the bulk materials examined in this study. The author further acknowledges the fellowship support received from the Next Generation EU project P2022ALSMP VISIO (CUP B53D23025290001) .
KeyWords: Multiphoton ionisation; Avalanche process; Blackbody radiation; Power law
DOI: 10.1016/j.jlumin.2025.121655