title: Analysis of the Thermo-Reflectivity Coefficient Influence Using Photothermal Pump-Probe Techniques.
abstract: Recent improvements in the modeling of photo-induced thermo-optical-mechanical effects have broadened the application of photothermal techniques to a large class of solids and fluids. During laser excitation, changes in optical reflectivity due to temperature variation may affect the photothermal signal. In this study, the influence of the reflectivity change due to heating is analyzed for two pump-probe photothermal techniques, thermal lens and thermal mirror. A linear equation for the temperature dependence of the reflectivity is derived, and the solution is tested using optical properties of semi-transparent and opaque materials. For semi-transparent materials, the influence of the reflectivity change in photothermal signals is less than 0.01%, while for opaque materials it is lower than 3%.
authors.affiliation: 1 Departamento de Física, Universidade Estadual de Maringá, Maringá, PR, Brazil.|2 Department of Chemistry and Biochemistry, Utah State University, Logan, UT, USA.
authors.forename: Vitor S
authors.initials: VS
authors.lastname: Zanuto
authors.affiliation: 1 Departamento de Física, Universidade Estadual de Maringá, Maringá, PR, Brazil.
authors.forename: Otávio A
authors.initials: OA
authors.lastname: Capeloto
authors.affiliation: 1 Departamento de Física, Universidade Estadual de Maringá, Maringá, PR, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Sandrini
authors.affiliation: 1 Departamento de Física, Universidade Estadual de Maringá, Maringá, PR, Brazil.
authors.forename: Luis C
authors.initials: LC
authors.lastname: Malacarne
authors.affiliation: 1 Departamento de Física, Universidade Estadual de Maringá, Maringá, PR, Brazil.
authors.forename: Nelson G C
authors.initials: NGC
authors.lastname: Astrath
authors.affiliation: 2 Department of Chemistry and Biochemistry, Utah State University, Logan, UT, USA.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Bialkowski
keywords: Photothermal phenomena; thermal lens; thermal mirror; thermo-reflectivity coefficient