Design and Fabrication of Coaxial Dual Core Optical Fiber Fan-in Device

TL;DR

This paper introduces a cold-processed coaxial dual-core fiber fan-in device that enables reliable fiber interconnection with low insertion loss, enhancing multi-core fiber applications.

Contribution

It presents a novel, fusion-splicing-free design and fabrication method for a coaxial dual-core fiber fan-in device using a V-groove substrate.

Findings

Average insertion loss of 2.15 dB for ring core at 980 nm

Average insertion loss of 1.25 dB for central core at 980 nm

Successful fabrication demonstrated through experimental characterization

Abstract

With the rapid development of information and communication technologies in recent years, the transmission capacity of single-core optical fibers has nearly reached its physical limit. Space-division multiplexing based on multi-core fibers offers an effective solution to this bottleneck. Multi-core fibers feature high integration and large transmission capacity, and their unique structural characteristics also give them special value in fiber-optic sensing applications. Among various types of multi-core fibers, coaxial dual-core fibers (CDCFs) have shown promising performance in particle trapping, signal emission, and spectral analysis. To enable reliable interconnection between different types of multi-core fibers and single-core fiber arrays, this paper presents the design and fabrication of a fan-in device for coaxial dual-core fibers with different core diameters. The proposed method relies solely on cold-processing techniques and does not require any fusion splicing or thermal processing. The device is implemented on a V-groove substrate. Through structural design, fabrication, and experimental characterization, the average insertion loss of the ring core and the central core at a wavelength of 980 nm is measured to be 2.15 dB and 1.25 dB, respectively, demonstrating the successful fabrication of a coaxial dual-core fan-in device.