Replication of Monolithic Micro Structured Optics in Quartz Glass using a Sol-Gel Process

Considerable investment costs due to complex single part production techniques are still a major obstacle inhibiting the high volume application of high quality micro structured (diffractive, hybrid) optics in quartz glass. We present a replication process which helps to overcome this fundamental trade off. Initially developed for the production of extraordinarily shaped laboratory quartz glass products a specific Sol-Gel process was adapted to meet the demands of diffractive (monolithic) optics fabrication. Significant effort has in particular been spent in the optimization of the minimum realizable feature size, the remaining surface roughness as well as the feature shape, depth and width accuracy within the replicated component. In our contribution we present the latest results at the example of binary diffractive beam shaping diffusers possessing a minimum feature size of 2 µm and a surface roughness (Ra) of less than 20 nm. Profilometric measurements and a characterization of the optical performance show that the process is qualified for the fabrication of high quality micro structured quartz glass optics.