First demonstration of 2μm data transmission in a low-loss hollow core photonic Bandgap fiber

The first demonstration of a hollow core photonic bandgap fiber suitable for high-rate data transmission at 2µm is presented. Using a custom built Thulium doped fiber amplifier, error-free 8Gbit/s transmission in an optically amplified data channel at 2008nm is reported for the first time

Anti-resonant hexagram hollow core fibers

Various simple anti-resonant, single cladding layer, hollow core fiber structures are examined. We show that the spacing between core and jacket glass and the shape of the support struts can be used to optimize confinement loss. We demonstrate the detrimental effect on confinement loss of thick nodes at the strut intersections and present a fabricated hexagram fiber that mitigates this effect in both straight and bent condition by presenting thin and radially elongated nodes. This fiber has loss comparable to published results for a first generation, multi-cladding ring, Kagome fiber with negative core curvature and has tolerable bend loss for many practical applications

Real-time prediction of structural and optical properties of hollow-core photonic bandgap fibers during fabrication

We formulate a simple model based on mass conservation to accurately predict the structural parameters of hollow-core photonic bandgap fibers from knowledge of the second stage preforms from which they are drawn. We show that combining this model with precalculated property maps can allow real-time prediction of the optical properties of manufactured fibers

Low-loss and low-bend-sensitivity mid-infrared guidance in a hollow-core–photonic-bandgap fiber

Hollow-core photonic-bandgap fiber, fabricated from high-purity synthetic silica, with a wide operating bandwidth between 3.1 and 3.7µm, is reported. A minimum attenuation of 0.13dB/m is achieved through a 19-cell core design with a thin core wall surround. The loss is reduced further to 0.05dB/m following a purging process to remove hydrogen chloride gas from the fiber - representing more than an order of magnitude loss reduction as compared to previously reported bandgap-guiding fibers operating in the mid-infrared. The fiber also offers a low bend sensitivity of &lt;0.25dB per 5cm diameter turn over a 300nm bandwidth. Simulations are in good agreement with the achieved losses and indicate that a further loss reduction of more than a factor of 2 should be possible by enlarging the core using a 37-cell design. <br/

Accurate modelling of fabricated hollow-core photonic bandgap fibers

We report a novel approach to reconstruct the cross-sectional profile of fabricated hollow-core photonic bandgap fibers from scanning electron microscope images. Finite element simulations on the reconstructed geometries achieve a remarkable match with the measured transmission window, surface mode position and attenuation. The agreement between estimated scattering loss from surface roughness and measured loss values indicates that structural distortions, in particular the uneven distribution of glass across the thin silica struts on the core boundary, have a strong impact on the loss. This provides insight into the differences between idealized models and fabricated fibers, which could be key to further fiber loss reduction

Recent advances in hollow-core photonic bandgap fibres

We review recent progress towards improving the transmission properties of hollowcore photonic band gap fibres including advances made in understanding the key issues limiting minimum loss and bandwidth in current fabricated structures

Hollow Core Fiber Technology for Data Transmission

We review our recent progress in developing hollow core photonic bandgap fibers for high capacity data transmission. Novel numerical and characterization tools developed to improve fiber performance and yield will be discussed