Refractive index of garnet films containing Ca and Ge

Refractive-index-vs-wavelength data are reported over a wavelength range of 0.56 to 0.97 μ for several garnets containing Ca2+ and Ge 4+ and various compositions of rare-earth ions. The experimental data were fitted to a two-term Sellmeier expression and a linear relation between index of refraction and number of Fe3+ ions was found for garnet composition with small rare-earth content.