The generation of mould patterns for multimode optical waveguide components by direct laser writing of SU-8 at 364 nm

Abstract

A commercial direct laser writing system operating at 364 nm wavelength is used to expose 90 µm thick layers of SU-8 on silicon. The resist structures are the basis for the fabrication of moulding tools that are used for the replication of multimode optical waveguide components. The influence of the laser power on the shape as well as on the sidewall roughness of the resist structures is studied in detail. The observed profiles are compared to a mathematical model based on the Gaussian beam approximation.