New Scheme of Hyperboloid Microlens for High-Average and High-Yield Coupling High-Power Lasers to Single-Mode Fibers

A new scheme of hyperboloid microlens (HM) employing automatic grinding and precise fusing techniques to achieve high-average and high-yield coupling efficiency from high-power 980-nm lasers into single mode fibers is proposed and demonstrated. The fiber endface of the HM exhibited a double-variable curvature in the major and minor axes that was characterized as a hyperboloid. By selecting half transverse length of the hyperbola and using fusing process to precise and quantitative controlling the required minor radius of curvature within 2.4-2.8 μ m and offset within 0.8 μ m, the HMs exhibited a high-average coupling efficiency of 83%. For fabricated high-coupling HMs, the result was also found that the tolerance of minor radius of curvature decreased as the offset increased. This study demonstrates that the proposed HMs through both automatic grinding and precise fusing techniques can achieve high-average and high-yield coupling efficiency better than any other grinding techniques to form asymmetric microlenses for utilizing in many low-cost lightwave interconnection applications.