20 February 2012 Numerical analysis of multi-photon parameters from ultrafast laser measurements
Author Affiliations +
We describe a unique mathematical/numerical model to analyze ultrafast laser experimental data and obtain two-photon (TPA) and multi-photon (MPA) absorption parameter(s). The material used to demonstrate the numerical method is a hybrid organic-inorganic nano-structured semiconductor quantum dot-polymer composite. Chemical, biological and engineering studies require advancements in TPA/MPA absorbers for microscopy, fluorescence, imaging, and microprocessing of materials. We illustrate the numerical method by fitting data from the well-known z-scan experimental method. Often an analytical model is used to analyze data from such experiments, which is limited in scope with certain restrictions on laser intensity and material thickness. A more general mathematical/numerical method that includes TPA/MPA and can be extended to free carrier absorption and stimulated emission is described. Under certain circumstances, we can also calculate the electron population density on every electronic level to demonstrate physical effects such as saturation. Additionally, we include diffraction in our numerical calculation so that the TPA/MPA can be obtained even for thick optical samples. We use the numerical method to calculate published z-scan measurements on quantum-dot CdS-polymer composites, and show excellent agreement with published analytical results.
© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
M. J. Potasek, M. J. Potasek, E. Parilov, E. Parilov, } "Numerical analysis of multi-photon parameters from ultrafast laser measurements", Proc. SPIE 8260, Ultrafast Phenomena and Nanophotonics XVI, 82600I (20 February 2012); doi: 10.1117/12.908677; https://doi.org/10.1117/12.908677

Back to Top