Abstract

A new process is described whereby excellent quality microlenses can be photolithographically patterned onto a glass. The glass whe exposed to Ultraviolet light followed by a thermal development initiates the formation of noble metal particles which in turn serve as nuclei for the growth of a microcrystalline phase from the homogeneous glass. This thermo-optically developed crystallized region is slightly more dense than the homogeneous glass. The contraction of the exposed region squeezes the soft unexposed glass beyond the original surface during the thermal schedule. When the appropriate photomask is used, opaque circles on a clear background, this effect produces spherical segments due the surface energy minimization. See Figure 1 for schematic of process and Figure 2 for actual SEM photomicrograph of formed lenses.

© 1987 Optical Society of America