Computer modeling of collection efficiency of laser excited fluorescence from a graphite furnace
A computer program has been developed with which it is possible to calculate the collection efficiency of an arbitrary combination of lenses and stops as a function of position in cartesian space. The program is based on a rigorous ray-tracing algorithm, and thus accounts for the effects of lens aberrations. It has been used to model three f/3 lens combinations configured to collect atomic fluorescence from a graphite furnace. Fluorescence was excited by a laser passing through a pierced mirror on the furnace axis and was collected on the same axis. The collection systems modelled included a symmetrical biconvex lens, a pair of matched plano-convex lenses, and a pair of matched achromats. Calculated single-point collection efficiencies differ significantly from those which would be expected, based on the solid angle subtended by the lenses. They range from less than 15% of the ideal value for the biconvex lens to nearly 100% for the achromats. Differences in performance are reduced when the efficiency is integrated over the 2 mm diameter of the exciting laser beam and the length of the graphite furnace.
Bibliographic Reference: Article: Spectrochimica Acta, Vol. 45B (1990) No. 10, pp. 1151-1166
Record Number: 199011822 / Last updated on: 1994-12-02
Original language: en
Available languages: en