Use of the reflectometry method in studies of the conditions at the end of a waveguide

An investigation was made of the possibility of using the reflectometry method to study changes in the reflection coefficient of a waveguide end resulting from changes in the refractive index of the medium adjoining the waveguide. Experimental methods were developed and their resolution was analyzed. The temperature dependences of the refractive indices of various liquids were investigated. The method was found to be suitable for determining changes in the refractive index of the ambient medium amounting to Δ n ~10^–3.