Fiber-Array-to-Chip Interconnections With Sub-Micron Placement Accuracy via Self-Aligning Chiplets

A self-aligning silicon chiplet approach is used on a silicon-on-insulator (SOI) substrate with ridge waveguides and grating couplers to enable interconnection with arrays of fibers. The approach is enabled by silicon micromachining and 3D printing, achieving highly scalable surface coupling of optical fibers to the gratings at repeatable sub-micron placement accuracies. The coupling efficiency relative to that of active fiber alignment at 1550 nm is 79%. Insertion points for 160 fibers across four chiplets are demonstrated. The design, fabrication and assembly processes together provide a potential technology for fiber-to-chip interconnects.