Abstract
The dynamic range of fiber-optic fluorescent probes such as single fibers and fiber bundles is calculated for strongly absorbing samples, such as process liquids, foodstuffs, and lubricants. The model assumes an excitation beam profile based on a Lambertian light source and uses analytical forms of the collection efficiency, followed by an Abel transformation and numerical integration. It is found that the effect of primary absorption of the excitation light and secondary absorption of the fluorescence is profound. For fiber bundles and bifurcated fiber probes, the upper accessible concentration limit is roughly given by the absorption length of the primary and secondary absorption. Fluorescence detectors that are placed at right angles to the excitation beam axis or collinear to the beam axis are equally strongly affected by secondary absorption. A probe in which the same fiber is used for excitation and for collection of the fluorescence emerges as the fiber probe with the largest accessible concentration range.
© 2012 Optical Society of America
Full Article | PDF ArticleMore Like This
Jianjun Ma, Yasser Chiniforooshan, Wenhui Hao, Wojtek J. Bock, and Zhi Yuan Wang
Opt. Express 20(4) 4805-4811 (2012)
T. Joshua Pfefer, Kevin T. Schomacker, Marwood N. Ediger, and Norman S. Nishioka
Appl. Opt. 41(22) 4712-4721 (2002)
J. Balaji, Kanchan Garai, Subhasis Chakrabarti, and Sudipta Maiti
Appl. Opt. 42(19) 3780-3784 (2003)