1 July 1990 Frustrated internal reflection fluorescent studies
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Proceedings Volume 1319, Optics in Complex Systems; (1990) https://doi.org/10.1117/12.22208
Event: 15th International Optics in Complex Systems, 1990, Garmisch, Germany
Abstract
The use of the evanescent wave produced in the second aediua vhen total reflection occurs at a boundary enables thickness ieasureents on a uanoetre scale to be aade sisultaneously with the highest lateral sagnification. The second aediun contains a siall concentration of fluorophores and the fluorescent . ission is measured. 2. DEPTH DEPENDENCE OF FLUORESCENCE Although the existence of fluorophores in the second sedius inevitably ieans a non-vanishing extinction coefficient K the very low concentration needed leads to an extinction coefficient of less than - iO. In calculating the electric field strength E in the evanesent wave no appreciable error results in putting K equal to zero. If the refractive index of the incident iediun is n1 that of the second zediun n2 and the angle of incidence e then for incident light with the electric vector perpendicular to the plane of incidence (''s''coiponent) the electric field at a depth z is given by: 1 5(z) . 2n1y1 e$2Z (1) 1n2$2 - n1y1 . SI 1. 7O where V1 n1k0 cos e $ nksin2e1 - nk and k0 2n/A where _1. 33 A is the wavelength in vacuo. The fluorescent flux frog a slab of thickness dx is proportional to Idz (Gingell et al'') so that the total signal 5T froa the unobstructed evanescent wave is given by SiO I 4n)je22dz 2n 5T (n$ + nvf) $2(n + nj) (2) Figure
© (1990) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Oliver S. Heavens, Oliver S. Heavens, } "Frustrated internal reflection fluorescent studies", Proc. SPIE 1319, Optics in Complex Systems, (1 July 1990); doi: 10.1117/12.22208; https://doi.org/10.1117/12.22208
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