Evaluation of thermal lens fringes using Hilbert and Fourier transform methods
Zehra Sarac, Ertan Ozturk, H. Gulay Birkok, Halit Taskin
article (Uluslararası, Hakemli) | Yazar(lar): Zehra Sarac, Ertan Ozturk, H. Gulay Birkok, Halit Taskin | Yıl: 2011 | Dergi/Kurum: IET SCIENCE MEASUREMENT & TECHNOLOGY | İndeks: WOS.SCI | DOI: 10.1049/iet-smt.2010.0045 — Özet: This study presents the analysis of thermal lens fringes obtained by heating the Nile-blue/eth
This study presents the analysis of thermal lens fringes obtained by heating the Nile-blue/ethanol solution with a He-Cd laser in aMichelson interferometer by utilising the Hilbert transform method (HTM) and the Fourier transform method (FTM) with a Gaussian filter. HTM and FTM are used for obtaining local phase and refractive index change maps of the interferograms. The results reveal that HTM creates harmonics in the frequency spectrum; hence, the signal cannot be filtered very accurately, whereas FTM with a Gaussian filter can create a smooth filtering effect.