Mid-Infrared Waveguide Array Inter-Chip Coupling Using Optical Quilt Packaging

A MEMS-based mid-infrared (MIR) chip-to-chip optical coupling technique, optical quilt packaging (OQP), is described. Numerical simulations are performed to predict performance and establish fabrication tolerances. The OQP fabrication process is described in detail and MIR inter-chip optical coupling between two waveguide arrays joined by OQP is characterized. The coupling loss between Ge-on-Si passive MIR waveguides is found to be ~ 4.1 dB, which is the lowest butt-coupling loss reported between two chips.