학술논문

Simultaneous determination of the spatial profile of the laser beam and vibrational-to-translational relaxation time by pulsed photoacoustics.
Document Type
Article
Source
Applied Physics B: Lasers & Optics. Jul2007, Vol. 88 Issue 2, p309-315. 7p. 4 Graphs.
Subject
*PHOTOACOUSTIC spectroscopy
*LASER beams
*RELAXATION (Nuclear physics)
*LASER spectroscopy
*TOMOGRAPHY
*ALGORITHMS
Language
ISSN
0946-2171
Abstract
Measuring the vibrational-to-translational relaxation time τV-T in gases is one of the applications of pulsed photoacoustic spectroscopy. Unfortunately, the spatial profile of the laser beam can significantly influence the accuracy of these measurements. Namely, minor changes in the spatial profile of the laser beam cause significant errors in the τV-T measuring. We present a method for simultaneous determination of the spatial profile of the laser beam and vibrational-to-translational relaxation time. It is based on the temporal shape of the photoacoustic pulse and utilizes a mathematical algorithm developed for photoacoustic tomography. [ABSTRACT FROM AUTHOR]