Optical constants of rare-earth substituted amorphous oxide-mix-based layers deposited to enable synthesis of magneto-optic garnets

Abstract Amorphous oxide mixes used to synthesise ferrite-type rare-earth (RE) substituted garnets and garnet-oxide nanocomposite layers are prepared on clear glass substrates by using RF magnetron sputter-deposition process. By using a combination approach employing custom-built spectrum-fitting software in conjunction with Swanepoel's envelope method, the spectral dispersion function of optical constants and the layer thicknesses are derived accurately from the transmission spectra of the as-deposited samples. The effects of excess metal-oxides added to the base material systems during the co-deposition process are found to affect the refractive index and the optical absorption coefficients of garnet-oxide composites. A number of optical constant datasets are presented, enabling the experimentalists to design nanophotonic or integrated-optics devices employing these functional materials. The garnet compositions characterized (deposited by RF sputtering) have only been reported in annealed garnet layers till present, however, the optical constants of as-deposited films are also of interest for the design of magnetic multilayers.