Barium titanate glass microspheres offer much higher index of refraction (refractive index) compared to other glass formulations. Refractive index is a measure of how light passes through an optical medium, making it a critical parameter in optical and optoelectronic devices.

Typically, the refractive index of a glass increases with its density. Barium titanate spheres with density as high as 4.4g/cc and index of refraction as high as 2.2 are currently available.