A dimension-reduction technique demonstrated by researchers at the University of South Carolina in Columbia and ChemIcon Inc. in Pittsburgh promises to expand fiber-based multiwavelength and multispecies chemical sensing applications. The technique incorporates a two-dimensional to one-dimensional, 608-fiber array that guides the light from a chemical probe to the detector for spectrographic analysis.The researchers prepared two 1-mm-diameter probes for the experiment, demonstrating stacked and side-by-side configurations of indicators for O2 and CO2 in sol-gel. A spectrograph measured the relative intensity of the luminescent response of the indicators at different concentrations of the gases.The team, which reported the work in Applied Spectroscopy, Vol. 55, No. 2, noted that the technique is most useful for producing multiwavelength concentration gradients or chemical images.