Scalable Fiber-Array-to-Chip Interconnections with Sub-Micron Alignment Accuracy

Experimental demonstration of optical fiber array-to-chip assembly is realized with a passive self-alignment mechanism and 3D-printed ferrules. The approach explored in this paper allows an array of fibers to be interconnected to chip-level grating couplers (GCs) with sub-micron level placement accuracy. The mechanical alignment (verified to be stable over one year) enables high relative coupling efficiency (>75%) at 1550 nm. It is shown that the proposed fiber interconnection technology is compatible with 2.5D heterogeneous integration technologies.