Chinese Optics Letters, 2020, 18 (2): 020602, Published Online: Jan. 7, 2020
Highly efficient excitation of LP01 mode in ring-core fibers by tapering for optimizing OAM generation Download: 1425次
Abstract
We have demonstrated the highly efficient excitation of the linearly polarized mode (LP01) in ring-core fibers (RCFs) by tapering the spliced point between the RCF and the standard single-mode fiber (SMF) to optimize all-fiber orbital angular momentum (OAM) generation. The tapering technique has been investigated theoretically and experimentally. Before tapering, only 50% of light can be coupled from SMFs to RCFs. The modal interference spectrum with an extinction ratio (ER) of ~9 dB is observed, showing that higher-order modes are excited in RCF. By tapering the spliced point, 90% of light is coupled, and the ER is minimized to be ~2 dB, indicating that the higher-order modes are effectively suppressed by tapering. Such tapered spliced points of RCF–SMF are further applied for all-fiber OAM generation. The efficiencies of OAM+1 and OAM?1 generation are found to be enhanced by approximately 11.66% and 12.41%, respectively, showing that the tapered spliced point of the RCF–SMF is a feasible way to optimize OAM generation.
Chunxiang Zhang, Fufei Pang, Huanhuan Liu, Lifei Chen, Junfeng Yang, Jianxiang Wen, Tingyun Wang. Highly efficient excitation of LP01 mode in ring-core fibers by tapering for optimizing OAM generation[J]. Chinese Optics Letters, 2020, 18(2): 020602.