Effect of grinding offset and radius of curvature on coupling efficiency of aspherical microlens for coupling high-power laser to fiber

We demonstrate a new scheme of aspherical microlens (ASM). By employing a single-step grinding with fully automatic technique to precisely and quantitatively control the grinding offset less than 0.5 μm and minor radius of curvature within 2.4-3.5 μm, the ASMs exhibited a high-average coupling efficiency of 84.5%. This study demonstrates that the proposed ASMs through a single-step grinding technique can achieve high-average coupling efficiency better than any other grinding techniques to form asymmetric microlenses.