New Scheme of Double-Variable-Curvature Microlens for Efficient Coupling High-Power Lasers to Single-Mode Fibers

A new scheme of a double-variable-curvature microlens (DVCM) employing a single-step grinding technique with fully automated fabrication for efficient coupling between high-power 980-nm laser diodes and single-mode fibers is proposed and demonstrated. The grinded fiber endface exhibited a double-variable curvature in the major axis, and was clearly observed for both major and minor axes after slight fusion polish. The perfect aspherical shape of the DVCM results in less grinding offset of 0.2 μm and better curvature radii control that leads to high average coupling efficiency of 83%. This clearly indicates that the performance of the DVCM can achieve high average coupling efficiency better than any other grinding techniques to form asymmetric microlenses. The versatility in double-variable-curvature design, fully automated fabrication, and the excellent performance of aspherical microlens makes the proposed DVCM extremely attractive for use in many lightwave interconnection applications.