A new basic analysis of pulsed photoacoustic signal using the finite differences method

¹ Département de physique, faculté des sciences de Meknès, Université Moulay Ismaïl, BP 4010, Beni M'hamed, Meknès, Morocco
² École Nationale des Sciences Appliquées de Tanger, Université Abdelmalek Essaâdi, route Ziaten, km 10, BP 1818, Tanger, Morocco
³ Department of Chemistry, University of Miami, Cox Science Building, 1301 Memorial Drive, PO Box 249118, Miami, FL, 33124-0431, USA

Corresponding author: nabil_benamar@yahoo.fr

Received: 10 November 2003
Revised: 8 April 2004
Accepted: 27 April 2004
Published online: 25 June 2004

Abstract

Pulsed photoacoustic spectroscopy provides information about optical, thermal and geometrical characteristics of opaque materials. The aim of this paper is the analysis of the applicability of the finite differences method to simulate the process by which pulsed photoacoustic signal is generated by a pulsed heat source, both in time and frequency domains. The present study is extended to a two-layers absorbing system. This method is free of the limitations imposed by special cases when the analytical methods are used to resolve heat diffusion equations. This approach is analyzed through the temperature and pressure variations in the photoacoustic cell.