Optical polymer aligner fabricated by 2pp for connecting angled fiber to an optical chip

This work presents a method for assembling photonic integrated circuits (PICs) with angled fibers using 3D-printed polymer micro-connector aligners fabricated via two-photon polymerization (2PP). We demonstrate a scalable solution for the passive alignment of fiber arrays with grating couplers, addressing photonic circuit packaging challenges. Mechanical testing performed in the work confirmed the reliable adhesion of the polymer aligner to the SiO₂ chip surface material, with an average pull-off force of 0.3 N. The average insertion loss was −13 dB at a wavelength of 1550 nm. The tolerance analysis revealed that the micro-aligner limits misalignment along one axis (Y), providing initial positioning with an accuracy limited by the printer’s resolution and the fiber’s fabrication tolerance. We estimate this accuracy to be ±2 μm, which significantly simplifies the subsequent fine alignment along the remaining degrees of freedom. A connection of an array of 5 fibers to the optical chip was achieved. The experimental results confirm the technology’s potential for R&D in applications requiring external fiber connections to PICs. Remaining challenges regarding array-level alignment accuracy are analyzed, and potential solutions are proposed.