Fiber optics, lasers, chemistry, fiber optic chemical sensors (FOCS), optics, and spectroscopy have been integrated to form the new technology of remote fiber spectroscopy (RFS). This method permits the development of ductile probes to detect and monitor ground-water contaminants. The key to this concept is the FOCS, a fiber termination with preselected chemical and physical properties. This is attached to the distal end of the fiber so that specific, sensitive analyses of ground-water constituents can be made. A single fiber is used for both excitation and for collection of the return signal, thus keeping the sensor small and optically simple.

The first FOCS being developed is to be used for both “early warning” and long-term monitoring of organic chloride. The chemical basis for this FOCS is a modified Fujiwara reaction. The FOCS, in conjunction with a field fluorimeter, have been used to make in situ measurements in a chloroform-contaminated well. Preliminary data indicate good agreement between the FOCS data and independent gas chromatography analysis of collected samples.