Solvent effect on dynamical TPA and optical limiting of BDMAS molecular media for nanosecond and femtosecond laser pulses
2011 (English)In: Journal of Physics B: Atomic, Molecular and Optical Physics, ISSN 0953-4075, E-ISSN 1361-6455, Vol. 44, no 3, 035103- p.Article in journal (Refereed) Published
The dynamical two-photon absorption (TPA) cross section as well as optical limiting of a 4,4'-bis(dimethylamino) stilbene (BDMAS) molecular medium for the nanosecond and femtosecond laser pulses is studied. This molecular medium can be described by a cascade three-level model in the visible light regime. Our numerical results show that the BDMAS molecular medium exhibits a strong optical limiting behaviour. The saturation TPA in the femtosecond time domain can be observed, and materials with larger nonlinear absorption cross sections would be much easier to saturate. Due to the contribution of the two-step TPA, the dynamical TPA cross section of BDMAS for nanosecond pulses is about three orders of magnitude larger than that for ultrashort femtosecond pulses. Special attention has been paid to the solvent effects on the optimal limiting performance. With an enhancement of the polarity of solvents, the dynamical optical limiting window becomes broader. In the origin of optical limiting, the dynamical TPA cross section of BDMAS decreases when the polarity of solvents increases, which is in good agreement with the experiment.
Place, publisher, year, edition, pages
2011. Vol. 44, no 3, 035103- p.
Atom and Molecular Physics and Optics
IdentifiersURN: urn:nbn:se:kth:diva-30525DOI: 10.1088/0953-4075/44/3/035103ISI: 000286512700009ScopusID: 2-s2.0-79551699275OAI: oai:DiVA.org:kth-30525DiVA: diva2:401899
QC 201103042011-03-042011-02-282011-03-04Bibliographically approved