Design and Fabrication of a Pre-aligned Free-space Optical Interconnection Device

In this paper, we report the design and fabrication of a pre-aligned free-space optical interconnection (FSOI) device. A simple FSOI prototype device is designed based on Gaussian beam propagation calculation. All optical components of a FSOI device were designed in a single one mask, and the alignment between the optical components was achieved in the mask design stage. All optical components including microlens array and micro mirrors were positioned in an out-of-plane fashion. The fabrication was based on a tilted Ultraviolet (UV) lithography of the SU-8 mold and fast replication using a UV curable polymer. This method allows the production of integrated optical systems similar to conventional optical benches in microscale and eliminates the need for tedious high-precision assembly.