Fluorescence saturation measurements of 3-pentanone

• Published in: Applied physics. B, Lasers and optics Vol. 93; no. 2-3; pp. 639 - 644
• Main Authors: Petersen, B. R., Ghandhi, J. B., Koch, J. D.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.11.2008; Springer
• Subjects: Ambient temperature; Atomic and molecular physics; Biological and medical applications; Cross sections; Engineering; Exact sciences and technology; Fluence; Fluorescence; Fluorescence and phosphorescence; radiationless transitions, quenching (intersystem crossing, internal conversion); Fundamental areas of phenomenology (including applications); Gaussian; Imaging; Lasers; Molecular properties and interactions with photons; Molecular spectra; Optical Devices; Optics; Photonics; Physical Chemistry; Physics; Physics and Astronomy; Quantum Optics; Saturation; Ultraviolet spectra; 33.50.-j; 33.20.Lg; Ketones; YAG laser; Laser induced fluorescence; Ultraviolet spectra; Measuring methods; Laser beam applications; Radiative lifetimes; Imagery; Solid state lasers; Ambient temperature; Saturated aliphatic compound; Organic compounds; Neodymium lasers
• ISSN: 0946-2171; 1432-0649
• DOI: 10.1007/s00340-008-3189-x

The saturation characteristics of 3-pentanone fluorescence were investigated in an ambient temperature and pressure cell by imaging the fluorescence produced by a focused quadrupled Nd:YAG laser beam. The onset of fluorescence saturation was observed at laser fluences around 0.06 J/cm 2 , which is only about 1.3% of estimates that assume a two-level model and use measured values of the fluorescence lifetime and absorption cross-section. A spatially resolved model indicated that the saturation fluence changed only 10% when a Gaussian profile was used instead of a top-hat profile. Laser sources with significantly different temporal profiles will have different threshold fluence levels, but the present results suggest that saturation effects should be monitored in planar laser-induced fluorescence imaging experiments using 3-pentanone.