Paper 14092-57
Paper 14092-57
Ultrashort pulses characterization by two-photon absorption signal in thick samples
On demand | Presented live 14 April 2026 
Abstract
Recently, we showed that it is possible to determine ultrashort pulses width and chirp (sign and magnitude) by nonlinear refraction (NLR) signals measured by the Nonlinear Ellipse Rotation (NER) technique in thick samples. Our single-beam method takes advantage of the material’s second-order dispersion, the group velocity dispersion (GVD), to reveal these two pulse properties. Now, we also have showed that the two-photon absorption (2PA) signal can be used to determine these same pulse properties. To do so, we carry out the open-aperture NER measurements in two optical glasses from Schott, SF6 and LaSF-N30, which present interesting NLR and 2PA properties, great optical quality, and well-known GVD. The results obtained simultaneously by our NLR and 2PA measurements are consistent and agree with the ones acquired by our previous work and with intensity autocorrelation measurements.
Presenter
Renato Mafra Moysés
University of Sao Paulo (USP) (Brazil)
He holds a Bachelor’s and a Master’s degree in Physics, both from the São Carlos Institute of Physics (IFSC), University of São Paulo (USP), Brazil. His research focuses on optics and photonics, with an emphasis on nonlinear optics, ultrafast laser pulses, and their photonic applications. He is currently pursuing a PhD degree focused on the characterization of semiconductors optical nonlinearities, aiming at applications in photonic devices, using both traditional and novel femtosecond-laser-based experimental techniques.