Study of light and matter interaction mechanisms in highly diffuse gain media

• Grant number: 12/05141-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: August 01, 2012
• End date: May 31, 2015
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Niklaus Ursus Wetter
• Grantee: Júlia Maria Giehl
• Host Institution: Instituto de Pesquisas Energéticas e Nucleares (IPEN). Secretaria de Desenvolvimento Econômico (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

The possibility to generate stimulated emission from disordered media (random laser) was already experimentally demonstrated in the 1990s. Such highly scattering media present various interesting properties which cannot be obtained with conventional lasers: simultaneous light emission at several wavelengths and emission at extremely low gain lines. Moreover, the microscopic dimension and the absence of polished surfaces are particularly interesting from the point of view of an integrated optical device.The research group coordinated by Prof. Dr. Niklaus Ursus Wetter has already produced two random lasers, one using a photonic crystal fiber (PCF) with its hollow core filled with a rodamine and rutile solution, and the other using disc shaped samples of laser active compacted nanopowder.In this work, our proposal is to proceed in this research, aiming a better amplification (higher fraction of stimulated emission) and the improvement of the emitted random laser beam quality (by using the same procedure adopted with PCF samples) for the integrated devices. For this purpose, we have established cooperation with the research group PSI (Polytechnic School, USP) for the use of ARROW integrated devices.The second focus of this working plan is to explore the active focalization of light by the scattering centers using external phase-modulation in order to investigate possible improvements and increase of resolution in turbid media.

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)

WETTER, NIKLAUS U.; GIEHL, JULIA M.; BUTZBACH, FELIX; ANACLETO, DANILO; JIMENEZ-VILLAR, ERNESTO. Polydispersed Powders (Nd3+:YVO4) for Ultra Efficient Random Lasers. PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION, v. 35, n. 4, APR 2018. (12/18162-4, 12/05141-9)

PONTUSCHKA, W. M.; GIEHL, J. M.; MIRANDA, A. R.; DA COSTA, Z. M.; ALENCAR, A. M.. Effect of the Al2O3 addition on the formation of silver nanoparticles in heat treated soda-lime silicate glasses. Journal of Non-Crystalline Solids, v. 453, p. 74-83, DEC 1 2016. (14/22102-2, 12/05141-9)