Determination of excitation profile and dielectric function spatial nonuniformity in porous silicon by using WKB approach

Abstract

We develop an analytical model based on the WKB approach to evaluate the experimental results of the femtosecond pump-probe measurements of the transmittance and reflectance obtained on thin membranes of porous silicon. The model allows us to retrieve a pump-induced nonuniform complex dielectric function change along the membrane depth. We show that the model fitting to the experimental data requires a minimal number of fitting parameters while still complying with the restriction imposed by the Kramers-Kronig relation. The developed model has a broad range of applications for experimental data analysis and practical implementation in the design of devices involving a spatially nonuniform dielectric function, such as in biosensing, wave-guiding, solar energy harvesting, photonics and electro-optical devices.

Publication DOI: https://doi.org/10.1364/OE.22.027123
Divisions: College of Engineering & Physical Sciences > School of Informatics and Digital Engineering > Mathematics
College of Engineering & Physical Sciences > Systems analytics research institute (SARI)
Additional Information: Funding: EPSRC and DSTL
Uncontrolled Keywords: thin film,optical properties,nanomaterials,refraction,refractivity profiles,Atomic and Molecular Physics, and Optics
Full Text Link:
Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
https://www.osa ... =oe-22-22-27123 (Publisher URL)
PURE Output Type: Article
Published Date: 2014-11-03
Published Online Date: 2014-10-24
Authors: He, Wei
Yurkevich, Igor V. (ORCID Profile 0000-0003-1447-8913)
Canham, Leigh T.
Loni, Armando
Kaplan, Andrey

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