Alignment-free integration of apertures and nontransparent hulls into 3D-printed micro-optics

The fabrication of 3D-printed micro-optical systems by femtosecond direct laser writing is state of the art. However, the inherent transparency of the lens mount, which is also made of photopolymer, causes a degradation of the image contrast due to stray light and scattering. Furthermore, apertures play a key role in optical design but cannot be directly integrated during 3D printing. Here, we present a superfine inkjet process for targeted filling of 3D-printed cavities in order to integrate apertures and nontransparent hulls without any alignment. Considerable contrast improvement and micro-optical systems with increased functionality are demonstrated.