Replication of Refractive Micro Opto-mechanical Components Made with Deep Lithography with Protons. P. Tuteleers, P. Vynck, B. Volckaerts, H. Ottevaere, V. Baukens, C. Debaes, A. Hermanne*, I. Veretennicoff , M. Kufner**, R. Einwächter**, G. Himmelsbach**, R. Schenk**, M. Küpper** and H. Thienpont Department of Applied Physics and Photonics (TW-TONA), Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium tel.: ++ 32 2 629 3613, fax: ++ 32 2 629 3450, Patrik.Tuteleers@vub.ac.be *Cyclotron Department VUB, Laarbeeklaan 103, 1090 Brussels, Belgium **Institute of Microtechnology Mainz, Carl-Zeiss-Strasse 18-20, D-55129 Mainz Deep Lithography with Protons (DLP) is a rapid prototyping technology for the fabrication of 3D micro-optical precision components. In this paper we will demonstrate how we made this DLP technology compatible with commercially available injection-molding and vacuum casting techniques, allowing to mass- replicate high-quality micro-optical modules at low cost. We will illustrate our technology by presenting optical characteristics of different refractive components made in optical-grade plastics such as polymethyl-methacrylate (PMMA), polycarbonate (PC) and semiconductor compatible plastics with high glass-transition temperatures such as COC. Introduction The technology of DLP [1,2] is a high-precision rapid prototyping technology for the fabrication of 3D micro-optical elements and micro-mechanical structures in PMMA. With this technology different optical components can be structured in one block to form monolithic micro-optical modules. In addition mechanical positioning and support structures can be integrated. This approach however is unpractical for mass- fabrication because an irradiation session, to obtain a single component, can take several hours. We investigated whether we could make DLP compatible with LIGA- adapted injection molding techniques, allowing for the mass replication of 3D plastic micro-optical components. We also looked at vacuum casting for the replication of micro-lenses. The concept of DLP The fabrication process of DLP consists of the following basic procedures: we start with a selective proton irradiation (8.3 MeV) of a 500 μm thick PMMA free-standing substrate followed by an etch-step that develops the irradiated regions. The impinging high-energy protons create well-defined domains with chemical properties different to those of the bulk-material. Irradiated domains can therefore be selectively dissolved with a special developer, since they show a higher solubility than the non-irradiated domains. The surfaces obtained with this procedure have a high optical quality and can be used e.g. as micro-mirrors [3], as shown in Figure 1a. Surface roughnesses of 32 nm are typical over a measuring length of 300μm. Alternatively to dissolving the irradiated zones we can swell them by exposing them to an organic monomer vapor such as MMA. This brings about a volume expansion resulting in a hemi-spherical surface. Hence refractive micro-lenses can be