Microbending effects in hollow-core photonic bandgap fibers

We developed a model for the study of how microbends affect the operation of hollow-core photonic bandgap fibers. Increased loss due to intermodal coupling is predicted. Preliminary experimental observations are in good agreement with the model’s predictions

Predicting Structural and Optical Properties of Hollow-Core Photonic Bandgap Fibers from Second Stage Preforms

We propose a simple theory based on mass conservation that allows accurate prediction of guidance properties in hollow-core photonic bandgap fibers (HC-PBGF) from knowledge of the second stage preforms from which the fibers are drawn

Optimizing the curvature of elliptical cladding elements to reduce leakage loss in antiresonant hollow core fibres

We study systematically the effect of the curvature of glass membranes on the confinement loss of an antiresonant negative curvature hollow core fibre. Optimum curvatures are found that can reduce the fibre loss by orders of magnitude

Exploring the effect of the core boundary curvature in hollow antiresonant fibers

Through numerical simulations, we systematically study the leakage loss properties of a simplified novel hollow antiresonant fiber in which the core is surrounded by semi-elliptical elements. These studies lead to new insight into the effect of the curvature of the core boundary in antiresonant fibers. We observe in particular that in our design, there exists an optimum curvature of the elements—which we quantify simply through the aspect ratio of the ellipses—for which the fiber’s leakage loss is minimized. Furthermore, it is shown that elliptical elements can lead to orders of magnitude loss reduction as compared with similar fibers with circular ones

Low loss, tightly coilable, hollow core photonic bandgap fibers for mid-IR applications

We describe low loss (50dB/km at 3.3µm) and low bend sensitivity mid-IR hollow core-photonic bandgap fiber. Gas sensing applications are highlighted by a methane spectrum recorded in our fiber

Recent advances in hollow fiber technology for telecoms applications

We review our recent work on the modelling, fabrication and characterization of hollow-core photonic bandgap fibers. We discuss the modal content of these fibers, as well as the opportunities and challenges presented by modal interactions in space division multiplexed transmission applications

Nondestructive measurement of the roughness of the inner surface of hollow core-photonic bandgap fibers

We present optical and atomic force microscopy measurements of the roughness of the core wall surface within a hollow core photonic bandgap fiber (HC-PBGF) over the [3×10-2 µm-1 to 30 µm-1] spatial frequency range. A recently developed immersion optical profilometry technique with picometer-scale sensitivity was used to measure the roughness of air-glass surfaces inside the fiber at unprecedentedly low spatial frequencies, which are known to have the highest impact on HC-PBGF scattering loss and, thus, determine their loss limit. Optical access to the inner surface of the core was obtained by the selective filling of the cladding holes with index matching liquid using techniques borrowed from micro-fluidics. Both measurement techniques reveal ultralow roughness levels exhibiting a 1/f spectral power density dependency characteristic of frozen surface capillary waves over a broad spatial frequency range. However, a deviation from this behavior at low spatial frequencies was observed for the first time, to the best of our knowledge

Optoelectronic oscillator with low temperature induced frequency drift

We demonstrate a hollow-core photonic bandgap fiber delay-line based 10 GHz Optoelectronic oscillator (OEO) with over 6 times less temperature induced frequency drift compared to a standard single mode fiber delay-line based OEO

Antiresonant hollow core fiber with an octave spanning bandwidth for short haul data communications

We report an effectively single mode tubular antiresonant hollow core fiber with minimum loss of ~25 dB/km at ~1200 nm, and an extremely wide low loss transmission window (lower than 30 dB/km loss from 1000 nm to 1400 nm and 6 dB bandwidth exceeding 1000 nm). Despite the relatively large mode field diameter of 32 µm, the fiber can be interfaced to SMF28 to produce fully connectorized samples. Exploiting an excellent modal purity arising from large modal differential loss and low intermodal coupling, we demonstrate penalty-free 10G on-off keying data transmission through 100m of fiber, at wavelengths of 1065, 1565 and 1963nm