Influence of chlorine on planar optical guide cladded with RbCl and AgCl

Thin films of RbCl and AgCl are prepared using vacuum evaporation technique and are characterized for Cl-2 effect through a number of techniques like XRD analysis, optical absorption and ellipsometry measurements. The time-series characterization with these techniques do show the expected differences with alternate pulsed chlorine and ambient air exposures. These are used as sensitive films on planar optical waveguide for Cl-2 gas. It is observed that, as cladding, they possess very good and selective chlorine sensing behaviour in ambient air over a wide concentration range of few (3) ppm-1.5%. (C) 1998 Elsevier Science B.V.