Nano-replication of diffractive optical elements in solgel derived glasses
A novel technological approach to generate glass micro- and nano-structures using in-house developed solgel materials, PDMS molding and thermal densification procedures was developed and presented. The synthesis of our solgel glass materials is based on the formation of particles of controlled size from organo-metallic compounds. The overall shrinkage during annealing of the gel material is negligible and does not imply crack formation. Silica, titania and binary oxides of silica titania oxide solgel materials are used in a nano-replication process. A two-step pattern transfer is employed to replicate the structure in glass: first a polydimethylsiloxane (PDMS) replica is obtained from a Si or PMMA/PI master structure, and secondly, a layer of solgel material is applied on the PDMS soft-replica to get micro-/nano-structure in glass after drying and annealing. Diffraction gratings and fresnel lenses with nano-scale features are realized and characterized.
diffractive optical elements solgel glass replication colloids