Exploring adaptive optics on focus-scan for nonlinear materials characterization

Fábio R P Dos Santos; Denise Valente; R E de Araujo; Diego Rativa

doi:10.1063/1.5080051

Exploring adaptive optics on focus-scan for nonlinear materials characterization

Rev Sci Instrum. 2019 Mar;90(3):033104. doi: 10.1063/1.5080051.

Authors

Fábio R P Dos Santos¹, Denise Valente², R E de Araujo¹, Diego Rativa²

Affiliations

¹ Laboratory of Biomedical Optics and Imaging, Federal University of Pernambuco, Recife, Brazil.
² Institute of Technological Innovation, University of Pernambuco, Recife, Brazil.

PMID: 30927774
DOI: 10.1063/1.5080051

Abstract

Z-scan is a well-established technique used to measure the nonlinear refractive index and absorption coefficient of thin and transparent materials. The method requires the displacement of the sample along the focus of a laser beam. Therefore, the Z-scan is not suitable for experiments where the sample cannot be axially translated. Here, we explore a deformable mirror to create controllable defocus aberrations, translating the focus of the beam through the sample, alternatively to the sample displacement. The technique is based on time behavior analysis of the light beam transmitted by the nonlinear sample, at different defocus configurations. The method is validated by measuring reference samples (CS₂ and SiO₂) and comparing them with the conventional Z-scan technique.