Efficient four-wave-mixing at 1.55 microns in a short-length dispersion shifted lead silicate holey fibre

We demonstrate four-wave-mixing in a 2.2m-long dispersion-tailored lead-silicate holey fibre with a conversion efficiency of -6dB and a bandwidth of ~30nm. The potential of dispersion-optimised soft-glass holey fibres for such applications is also discussed

Development of Highly Nonlinear Extruded Lead Silicate Holey Fibers with Novel Dispersive Properties

Holey Fibers (HFs) have generated enormous interest from areas as diverse as spectroscopy, metrology, biomedicine, imaging, telecommunication, industrial machining and the military. Recently, HFs made from compound glasses with high nonlinear refractive indices have attracted much attention for nonlinear device applications. In this study we used Lead-silicate (Pb) glass, which has proven to be a promising material for high nonlinearity HFs. Pb glasses offer high thermal and crystallization stability and less steep viscosity-temperature-curves with low softening temperatures, which allow the use of extrusion as an alternative fiber preform fabrication technology. Pb-HFs has a high material nonlinear refractive index and the index between the glass core and the air filled cladding enables tight mode confinement which results in a low effective area and thereby a high nonlinear coefficient. In addition, Pb has large normal material dispersion and bulk glass zero dispersion (ZD) wavelength at 1970nm, the tailorability of the cladding structure enables high flexibility in the design of the dispersion profile facilitating nonlinear effects, especially by the choice of ZD wavelengths at near IR region. This paper presents the development of small-core high-nonlinearity non-silica HFs with unique dispersive properties for compact nonlinear optics devices operating at low powers. To date, we managed to produce low-loss (2dB/m at 1550nm and ~1.5dB/m at 1060nm) Pb-HFs with very high nonlinearity coefficient up to ~2000W.A dispersion model simulated using finite element method has demonstrated that Pb glass HFs with core size of 1.7µm are anticipated to enable ZD at 1060nm and with very high nonlinearities, which should allow efficient supercontinuum generation in compact devices using commonly available femto-second lasers as the pump sources. These results show that Pb-HFs are indeed promising components that contribute to the significant advancement in the miniaturization of compact nonlinear devices operating at low powers and offering appropriate dispersion

Recent developments in fibre technology and its application within high speed optical communications

Recent advances in optical fibre technology, most notably in the area of microstructured fibres, high power rare-earth doped fibres, and superstructured fibre Bragg gratings offer a host of new opportunities within future high speed communication systems. Herein we review the increased range of waveguide characteristics that can now be obtained within fibre with an emphasis on both fibre nonlinearity and dispersion control, and describe the latest advances in the design and fabrication of fibre Bragg gratings for the manipulation and shaping of ultrashort pulses. We then outline how such components can be integrated into various all-optical processing devices for high speed optical communication systems focusing in particular on data retiming and OTDM add-drop multiplexing

High-nonlinearity dispersion-shifted lead-silicate holey fibers for efficient 1-µm pumped supercontinuum generation

This paper reports on the recent progress in the design and fabrication of high-nonlinearity lead-silicate holey fibers (HFs). First, the fabrication of a fiber designed to offer close to the maximum possible nonlinearity per unit length in this glass type is described. A value of gamma = 1860 W-1 · km-1 at a wavelength of 1.55 µm is achieved, which is believed to be a record for any fiber at this wavelength. Second, the design and fabrication of a fiber with a slightly reduced nonlinearity but with dispersion-shifted characteristics tailored to enhance broadband supercontinuum (SC) generation when pumped at a wavelength of 1.06 µm - a wavelength readily generated using Yb-doped fiber lasers - are described. SC generation spanning more than 1000 nm is observed for modest pulse energies of ~ 100 pJ using a short length of this fiber. Finally, the results of numerical simulations of the SC process in the proposed fibers are presented, which are in good agreement with the experimental observations and highlight the importance of accurate control of the zero-dispersion wavelength (ZDW) when optimizing such fibers for SC performance

Low walk-off Kerr-shutter using a dispersion-shifted lead silicate holey fiber

We present, for the first time to our knowledge, the use of a dispersion-shifted soft-glass holey fiber (HF) in a Kerr-shutter configuration. Wavelength conversion of 10-Gb/s data pulses is achieved in the C-band using just 2.1 m of a lead-silicate HF with a nonlinear parameter gamma of 164 W-1 ldr km-1. The low dispersion and the short length of the fiber enable short switching windows to be realized

Mid-IR supercontinuum generation from non-silica microstructured optical fibers

In this paper, the properties of nonsilica glasses and the related technology for microstructured fiber fabrication are reviewed. Numerical simulation results are shown using the properties of nonsilica microstructured fibers for mid-infrared (mid-IR) supercontinuum generation when seeding with near-IR, 200 fs pump pulses. In particular, bismuth glass small-core fibers that have two zero-dispersion wavelengths (ZDWs) are investigated, and efficient mid-IR generation is enabled by phase-matching of a 2.0 µm seed across the upper ZDW into the 3-4.5 µm wavelength range. Fiber lengths considered were 40 mm. Simulation results for a range of nonsilica large-mode fibers are also shown for comparison

Towards zero dispersion highly nonlinear lead silicate glass holey fibres at 1550nm by structured-element-stacking

We report the fabrication of lead-silicate holey fibres with a high nonlinearity up to 414W and low dispersion at 1550nm using a new fabrication technique based on the stacking of extruded structured elements

Recent advances in highly nonlinear microstructured optical fibers

Microstructured fiber technology offers the prospects of fibers with unique nonlinear and dispersive properties. We review the latest developments in the field and progress towards various application optimized fiber types

Non-silica highly nonlinear holey fibers for telecommunications applications

We report on recent development in the fabrication and characterization of small-core lead-silicate and bismuth-oxide glass holey fibers. These fibers exhibit an effective nonlinearity three orders of magnitude higher than standard silica fibers, offering the prospect of compact, nonlinear devices operating at low powers

Broadband supercontinuum generation in an extremely nonlinear extruded lead silicate holey fiber using weak fs pulses

Broadband supercontinuum generation at 1.06µm spanning > 1000nm and extending to the visible is observed in a dispersion optimized holey fiber with a record-high nonlinearity (1860W at 1.55µm), for launched pulse energies < 100pJ