Very efficient sampling technique for fiber-remote optical emission spectroscopy of aqueous solutions

Abstract

We have measured fluorescence from a waveguide formed by a falling cylindrical stream of liquid. The configuration is suited to taking measurements from liquids with any refractive index, such as aqueous solutions. The parameters which determine the stream stability have been investigated, and the optical collection efficiency has been mathematically modelled. We have produced streams up to 350 mm long with a 2.5 mm diameter, and measured a fluorescence collection enhancement factor of 9 from a 100 mm long, 1 mm diameter stream