A novel lensed fiber for high-efficiency coupling between an single-mode fiber (SMF) and a high-power laser diode (LD) with large astigmatism of 176 µm is proposed and demonstrated. We experimentally confirmed that the proposed lensed fiber had a minimum coupling loss of 2.5 dB including a reflection loss of 0.3 dB at both ends of the fiber. In addition the new configuration had a long working distance of 67 µm. We also investigated the tolerance characteristics for various displacements.
[IEEE ]PDF Article