Time-dependent thermal lens signal with tightly focused laser beam excitation

I I. V. Capél (Department of Physics, Universidade Estadual de Maringá 1 , Maringá, Paraná 87020-900,) J J. W. Berrar (Department of Physics, Universidade Estadual de Maringá 1 , Maringá, Paraná 87020-900,) B B. Anghinoni (Department of Physics, Universidade Estadual de Maringá 1 , Maringá, Paraná 87020-900,) V V. G. Camargo (Department of Physics, Universidade Estadual de Maringá 1 , Maringá, Paraná 87020-900,) M M. L. Baesso (Department of Physics, Universidade Estadual de Maringá 1 , Maringá, Paraná 87020-900,) L L. C. Malacarne (Department of Physics, Universidade Estadual de Maringá 1 , Maringá, Paraná 87020-900,) M M. Franko (Laboratory for Environmental and Life Sciences, University of Nova Gorica 2 , Nova Gorica SI-5000,) B B. Lendl (Institute of Chemical Technologies and Analytics, Technische Universität Wien 3 , Vienna 1060,) N N. G. C. Astrath (Department of Physics, Universidade Estadual de Maringá 1 , Maringá, Paraná 87020-900,)

Abstract

This work theoretically and numerically explores the effects of varying the excitation beam radius along the propagation axis on time-dependent thermal lensing phenomena. We investigate how changes in sample length and geometrical parameters of the setup influence the thermal lens signal. Specifically, for samples obeying the Beer–Lambert law of optical absorption, an exponential relation between sample length and excitation beam waist is found to accurately describe the point of maximum magnitude of the steady-state signal, offering a reliable route for signal optimization. Understanding the photothermal effects under tightly focused beam excitation is essential to enhance overall sample characterization, being particularly relevant to modern applications in thermal lens microscopy.

Article Details

Volume / Issue Vol. 138, Issue 12
Published September 28, 2025
ISSN 0021-8979
Publisher American Institute of Physics

Journal Info

Journal of Applied Physics

American Institute of Physics

ISSN: 0021-8979 Physical Sciences

Authors (9)

I

I. V. Capél

Department of Physics, Universidade Estadual de Maringá 1 , Maringá, Paraná 87020-900,

J

J. W. Berrar

Department of Physics, Universidade Estadual de Maringá 1 , Maringá, Paraná 87020-900,

B

B. Anghinoni

Department of Physics, Universidade Estadual de Maringá 1 , Maringá, Paraná 87020-900,

V

V. G. Camargo

Department of Physics, Universidade Estadual de Maringá 1 , Maringá, Paraná 87020-900,

M

M. L. Baesso

Department of Physics, Universidade Estadual de Maringá 1 , Maringá, Paraná 87020-900,

L

L. C. Malacarne

Department of Physics, Universidade Estadual de Maringá 1 , Maringá, Paraná 87020-900,

M

M. Franko

Laboratory for Environmental and Life Sciences, University of Nova Gorica 2 , Nova Gorica SI-5000,

B

B. Lendl

Institute of Chemical Technologies and Analytics, Technische Universität Wien 3 , Vienna 1060,

N

N. G. C. Astrath

Department of Physics, Universidade Estadual de Maringá 1 , Maringá, Paraná 87020-900,