Open AccessFemtosecond two-photon absorption measurements based on the accumulative photo-thermal effect and the Rayleigh interferometer
Author(s) -
Luis G. Rodríguez,
Hyo Yang Ahn,
Kevin D. Belfield
Publication year - 2009
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.17.019617
Subject(s) - optics , femtosecond , interferometry , materials science , refractive index , interference (communication) , absorption (acoustics) , rayleigh scattering , laser , two photon absorption , lens (geology) , thermal , physics , channel (broadcasting) , electrical engineering , meteorology , engineering
A rapid, straightforward method for measuring the two-photon absorption cross sections in liquid samples based on both the accumulative photo-thermal effect and the Rayleigh interferometery is described and demonstrated. This technique combines the sensitivity of the thermal lens approach and the accuracy of interferometry techniques. Focusing a high repetition rate laser beam in the sample, generating a localized change in its refractive index, induces the photo-thermal phase shift. By recording and processing two interference patterns, this technique allows the rapid estimation of the two-photon absorption cross section of the sample. Significantly, the experimental results demonstrate that this new method can be used with both fluorescent and non-fluorescent samples.