Birefringent anti-resonant hollow-core fiber

TL;DR

This paper presents the design, fabrication, and characterization of a birefringent, polarization-maintaining anti-resonant hollow-core fiber with low loss and broadband operation, suitable for advanced optical applications.

Contribution

It introduces a novel birefringent hollow-core fiber with reduced symmetry, achieving high birefringence and low loss, advancing the practical use of hollow-core fibers.

Findings

Measured group birefringence of 4.4x10^-5 at 1550 nm

Fiber loss of 0.46 dB/m at 1550 nm

Broadband operation with simple structure

Abstract

Hollow-core fibers have demonstrated record performance in applications such as high-power pulse delivery, quantum computing, and sensing. However, their routine use is yet to become reality. A major obstacle is the ability to maintain the polarization state of light over a broad range of wavelengths, while also ensuring low attenuation and single-mode guidance. Here we simulated, fabricated and characterized a single-mode polarization-maintaining anti-resonant hollow-core fiber. The birefringence was achieved by introducing resonators of different thicknesses, thereby creating reduced symmetry in the structure. The measured group birefringence of 4.4x10-5 at 1550 nm is in good agreement with the calculated group birefringence from the simulations. This corresponds to a phase birefringence of 2.5x10-5 at 1550 nm. The measured loss of the fiber was 0.46 dB/m at 1550 nm. With its simple structure, low loss, and broadband operation this polarization-maintaining anti-resonant hollow-core fiber is a serious contender for applications in gas-based nonlinear optics and communications.