Abstract

There has been great interest in composite thin film materials in order to relieve the material constraints on refractive indices as well as to reduce the number of layers required in coating design (1, 2). We chose to study composite films of hafnia (HfO2) and magnesium fluoride (MgF2) because HfO2 is known to be a hard and durable high-index material in the near ultra-violet (near-UV) region while MgF2 has wide transmission spectral range extended into vacuum UV region in addition to being a highly durable low-index material (3, 4). We investigated composite films of various HfO2 and MgF2 compositions in search of a mixture which has better transparency in the UV region and relatively high refractive indices in the UV and visible spectral region.

© 1995 Optical Society of America