Nonlinear spectroscopy in ion doped materials

• Grant number: 23/16133-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2024
• End date: December 31, 2024
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Tomaz Catunda
• Grantee: Lucius Borges de Souza
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

The purpose of this Scientific Initiation project is the study of non-linear spectroscopy in solids (crystals and glasses) doped with rare earth ions, materials of great relevance in photonics, lasers, optical amplifiers, luminescence, etc. We are particularly interested in the effect of Population Lens, that is, variations in the refractive index due to the population of the metastable excited state, caused by the difference in polarizability between the excited and ground states. In this study we will use the time-resolved Z-scan technique, which has proven to be very suitable for slow systems (response times greater than ~ 10-5 sec.) which is the case of solids doped with rare earths or transition metals. In this technique we use cw (continuous) lasers modulated with a chopper (a mechanical modulator). Two experiments were proposed, the study of systems doped with Tb3+ with excitation using an Ar+ laser (488 nm) and Er3+ with excitation from an Er3+ laser tunable at ~ 1.5 mm.Finally, the theme seems quite suitable for an IC project as it involves interesting experiments (research topics of current relevance) but also didactic and accessible to an IC student. Finally, I consider that the candidate has a very good academic performance and has already demonstrated a talent for Experimental Physics in work carried out in the group.