Microlens-Assisted Expanded Beam Technique for Coupling of Laser Source to Photonic Integrated Circuit

Efficient coupling interface is crucial for integrating densely-packed photonic sub-assemblies. This study presents a microlens-assisted expanded-mode technique for coupling light from a laser diode into a photonic-integrated-circuit edge coupler. The results show good coupling with relaxed alignment tolerances, paving the way for efficient free-space optical interconnects in chiplet-based photonic packaging.