Highly efficient wideband and polarization-insensitive SMF-ARF coupling strategy with low back-reflection

TL;DR

This paper introduces a lensed-fiber coupling method for anti-resonant fibers that achieves high efficiency, low back-reflection, and polarization insensitivity, suitable for high-capacity optical networks.

Contribution

It presents a novel coupling strategy optimized for low-loss, polarization-insensitive connections between single-mode and anti-resonant fibers.

Findings

Insertion loss of 1.2 dB at 1550 nm

Back-reflection of -36.22 dB at 1550 nm

Spectral stability below 0.72 dB across 1500-1600 nm

Abstract

We propose a lensed-fiber based coupling strategy for low-loss interconnection between single-mode fibers and anti-resonant fibers. By optimizing structural and geometric parameters, the design simultaneously achieves high coupling efficiency and suppressed back-reflection. Experimental results demonstrate an insertion loss of 1.2 dB and back-reflection of -36.22 dB at 1550 nm, with excellent spectral stability (below 0.72 dB variation across 1500-1600 nm) and polarization insensitivity (below 0.4 dB polarization dependent loss). The compact structure not only facilitates the fabrication process, but also enables seamless ARF integration into existing optical networks, thereby addressing critical demands for high-capacity data transmission.