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
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, "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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