30.7 Tb/s (96x320 Gb/s) DP-32QAM transmission over 19-cell photonic band gap fiber

We report for the first time coherently-detected, polarization-multiplexed transmission over a photonic band gap fiber. By transmitting 96 x 320-Gb/s DP-32QAM modulated channels, a net data rate of 24 Tb/s was obtained

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

How to make the propagation time through an optical fiber fully insensitive to temperature variations

Propagation time through standard (solid core) optical fibers changes with the temperature at a rate of 40 ps/km/K. The thermo-optic effect in silica glass accounts for about 95% of this change, and thus, hollow-core fibers, in which the majority of optical power propagates through an air rather than a glass core, can have this sensitivity greatly reduced. To date, we have demonstrated a sensitivity as low as 2 ps/km/K, this value being limited by thermally induced fiber elongation. In this paper, we predict and experimentally demonstrate that the thermal sensitivity of the propagation time can be reduced to zero (or even made negative) in hollow-core photonic bandgap fibers by compensating the thermally induced fiber elongation with an equal and opposite thermally induced group velocity change (i.e., by making the light travel faster through the elongated fiber). This represents the ultimate fiber solution for many propagation time-sensitive applications

First demonstration of a broadband 37-cell hollow core photonic bandgap fiber and its application to high capacity mode division multiplexing

We report fabrication of the first low-loss, broadband 37-cell photonic bandgap fiber. Exploiting absence of surface modes and low cross-talk in the fiber we demonstrate mode division multiplexing over three modes with record transmission capacity

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

Towards high-capacity fibre-optic communications at the speed of light in vacuum

Wide-bandwidth signal transmission with low latency is emerging as a key requirement in a number of applications, including the development of future exaflop-scale supercomputers, financial algorithmic trading and cloud computing. Optical fibres provide unsurpassed transmission bandwidth, but light propagates 31% slower in a silica glass fibre than in vacuum, thus compromising latency. Air guidance in hollow-core fibres can reduce fibre latency very significantly. However, state-of-the-art technology cannot achieve the combined values of loss, bandwidth and mode-coupling characteristics required for high-capacity data transmission. Here, we report a fundamentally improved hollow-core photonic-bandgap fibre that provides a record combination of low loss (3.5 dB km-1) and wide bandwidth (160 nm), and use it to transmit 373 x 40 Gbit s-1 channels at a 1.54 ms km-1 faster speed than in a conventional fibre. This represents the first experimental demonstration of fibre-based wavelength division multiplexed data transmission at close to (99.7%) the speed of light in vacuu

A first glance at coherent optical transmission using photonic bandgap fiber as a transmission medium

Photonic bandgap fibers (PBGF) potentially offer a very substantial increase of capacity per fiber over solid core fibers. We review transmission experiments using PBGF and their viability for next-generation transmissions systems

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