Study of the zincblende polycrystalline semiconductors nonlinearities: spectral and spatial dependences

• Grant number: 19/00638-1
• Support type: Regular Research Grants
• Duration: May 01, 2019 - October 31, 2021
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal researcher: Lino Misoguti
• Grantee: Lino Misoguti
• Home Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

The advent of reliable commercial optical parametric amplifiers (OPA), which deliveries tunable femtosecond laser pulses in a broad spectral range, paved the way for determination of the materials optical nonlinearities spectra. In special, in this project we will study the spectral dependence of nonlinear optical properties of polycrystalline media, specially the third-order one such as the nonlinear refraction (NR) and nonlinear absorption (NA) by mean of nonlinear ellipse rotation (NER) measurements, using tunable ultrashort femtosecond pulses. Among several important nonlinear media, we will study the family of the zincblende structure polycrystalline semiconductors since some of these semiconductors present very high nonlinearities, but also, an interesting spatial inhomogeneity. Preliminary measurements showed that the NR signals measured by NER in zinc selenide (ZnSe) and zinc sulfide (ZnS), two well-known and well-characterized zincblende semiconductors, are different depending of the laser light incidence positions, probably related to the polycrystalline nature of the semiconductors. The commercial ZnSe and ZnS windows are normally polycrystallines samples with 60-100 mm grain size randomly distributed inside the bulk. Our results showed that ZnSe and ZnS are completely isotropic and anisotropic in the linear and the nonlinear optical point of view, respectively. Since this effect was never reported in the literature and considering that it is an important class of nonlinear media, in this project, we intend to study in detail the origin of the inhomogeneity and also determine the NR and NA spectra of different polycrystalline media taking into account the influence of the grain crystallographic orientation and laser polarization. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

FERNANDES, J. C.; BARBANO, E. C.; SIQUEIRA, J. P.; MISOGUTI, L. Small difference between the nonlinear refractions of normal and deuterated solvents measurable by nonlinear ellipse rotation. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS, v. 38, n. 9, p. 2663-2668, SEP 1 2021. Web of Science Citations: 0.

MELHADO, MARLON S.; DE SOUZA, TIAGO G. B.; ZILIO, SERGIO C.; BARBANO, EMERSON C.; MISOGUTI, LINO. Discrimination between two distinct nonlinear effects by polarization-resolved Z-scan measurements. Optics Express, v. 28, n. 3, p. 3352-3360, FEB 3 2020. Web of Science Citations: 2.

GOMES, J. A. C.; BARBANO, E. C.; MISOGUTI, L. Cross-section profile of the nonlinear refractive index of Gorilla Glass obtained by nonlinear ellipse rotation measurements. APPLIED OPTICS, v. 58, n. 28, p. 7858-7861, OCT 1 2019. Web of Science Citations: 0.