Connecting Technologies for Coaxial Dual Core Optical Fiber

Coaxial dual core optical fiber (CDCF) with a lensed tip can be used for microparticle trapping, shooting, and spectra analyzing. In this paper, we introduce the connection technology of CDCFs. On the one hand, the CDCFs can be fusion spliced easily and quickly by using the single-mode fiber (SMF) splicing machine, because they have a completely axisymmetric structure. On the other hand, a fan-in device based on the principle of “vanishing core” is designed, and the insertion loss due to fabrication process error is analyzed. Fan-in devices are fabricated and tested. The average insertion loss of the annular core and central core is 1.48 dB and 0.76 dB, respectively.