EXPERIMENTAL-DETERMINATION OF THE THERMOOPTICAL PROPERTIES OF ZIRCONIUM DIOXIDE COATINGS

An experimental determination of optical constants and thermal optical properties of thin solid films is described in which the test element is a zirconium dioxide film coated onto the end face of a multimode f used silica optical fibre. Refractive index and thermal optic coeffici ent (dn/dT) of the thin films for wavelengths between 700 nm and 900 n m were experimentally measured from the reflectance spectrum. The chan ge in reflectance for the test element was measured as a function of t emperature. The use of the results in the design of a thin-film fibre optic temperature sensor is discussed.