Analyzing laser plasma interferograms with a continuous wavelet transform ridge extraction technique: the method
Authors: Tomassini P., Giulietti A., Gizzi LA., Galimberti M., Giulietti D., Borghesi M., Willi O.
Autors Affiliation: CNR, Ist Fis Atom & Mol, Intense Laser Irradiat Lab, Area Ric Pisa, I-56124 Pisa, Italy;
Univ Pisa, CNR, Dipartimento Fis, Ist Fis Atom & Mol,Intense Laser Irradiat Lab, Pisa, Italy;
Ist Nazl Fis Mat, Unita Pisa, Pisa, Italy;
Queens Univ Belfast, Dept Pure & Appl Phys, Belfast, Antrim North Ireland;
Blackett Lab, London, England;
Univ London Imperial Coll Sci Technol & Med, London, England
Abstract: Laser plasma interferograms are currently analyzed by extraction of the phase-shift map with fast Fourier transform (FFT) techniques [Appl. Opt. 18, 3101 (1985)]. This methodology works well when interferograms are only marginally affected by noise and reduction of fringe visibility, but it can fail to produce accurate phase-shift maps when low-quality images are dealt with. We present a novel procedure for a phase-shift map computation that makes extensive use of the ridge extraction in the continuous wavelet transform (CWT) framework. The CWT tool is flexible because of the wide adaptability of the analyzing basis, and it can be accurate because of the intrinsic noise reduction in the ridge extraction. A comparative analysis of the accuracy performances of them new tool and the FFT-based one shows that the CWT-based tool produces phase maps considerably less noisy and that it can better resolve local inhomogeneties. (C) 2001 Optical Society of America.
Journal/Review: APPLIED OPTICS
Volume: 40 (35) Pages from: 6561 to: 6568
KeyWords: plasma laserDOI: 10.1364/AO.40.006561Citations: 59data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2021-07-25References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here