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 Cl2 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 Cl2 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%.