S. Asimakis

Bismuth glass holey fibers with high nonlinearity.

We report on the progress of bismuth oxide glass holey fibers for nonlinear device applications. The use of micron-scale core diameters has resulted in a very high nonlinearity of 1100 W-1 km-1 at 1550 nm. The nonlinear performance of the fibers is evaluated in terms of a newly introduced figure-of-merit for nonlinear device applications. Anomalous dispersion at 1550 nm has been predicted and experimentally confirmed by soliton self-frequency shifting. In addition, we demonstrate the fusion-splicing of a bismuth holey fiber to silica fibers, which has resulted in reduced coupling loss and robust single mode guiding at 1550 nm.

High-nonlinearity dispersion-shifted lead-silicate holey fibers for efficient 1-/spl mu/m 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 /spl gamma/=1860 W/sup -1//spl middot/km/sup -1/ at a wavelength of 1.55 /spl mu/m 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 /spl mu/m-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 /spl sim/ 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.

Towards efficient and broadband four-wave-mixing using short-length dispersion tailored lead silicate holey fibers

We demonstrate four-wave-mixing based wavelength conversion at 1.55 mum in a 2.2 m-long dispersion-shifted lead-silicate holey fiber. For a pump peak power of ~6 W, a conversion efficiency of -6 dB is achieved over a 3-dB bandwidth of ~30 nm. Numerical simulations are used to predict the performance of the fiber for different experimental conditions and to address the potential of dispersion-tailored lead silicate holey fibers in wavelength conversion applications utilizing four-wave-mixing. It is shown that highly efficient and broadband wavelength conversion, covering the entire C-band, can be achieved for such fibers at reasonable optical pump powers and for fiber lengths as short as ~2 m.

2R regenerator based on a 2-m-long highly nonlinear bismuth oxide fiber

We report the use of a 2-m-long Bismuth Oxide fiber with an ultra-high nonlinearity of ~1100 W(-1)km(-1) in a simple 2R regeneration experiment based on self phase modulation and offset filtering. Numerical simulations and experimental results confirm the suitability of this kind of fiber for 2R regeneration. An improvement in receiver sensitivity of more than 5 dB at 10 Gb/s and 2 dB at 40 Gb/s is achieved.

Advances in microstructured fiber technology

We review our recent progress in the area of microstructured fiber design, fabrication and applications with particular emphasis on the control of both the nonlinearity and dispersion.

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 ¿ of 164 W-1 · km-1. The low dispersion and the short length of the fiber enable short switching windows to be realized.

A 2-m-long reshaping regenerator based on a highly nonlinear bismuth oxide fiber

We report the use of a 2-m-long highly nonlinear bismuth oxide fiber in a simple 2R regeneration scheme. An improvement in receiver sensitivity of ~5 dB at 10-Gbit/s and ~2 dB at 40-Gbit/s is demonstrated

Nonlinearity and dispersion control in small core lead silicate holey fibers by structured element stacking

We report a new fabrication approach that combines the benefits of extrusion and stacking, which is capable of realising high-nonlinearity lead-silicate glass holey fibers with tailorable dispersion characteristics. We also present optimised fiber designs offering dispersion-shifted and flattened performance at 1.55 mum

High Nonlinearity Holey Fibers: Design, Fabrication and Applications

We describe our recent progress in the development of next-generation small-core holey fibers (HFs) with unique dispersive and nonlinear properties. We report the use of Genetic Algorithms to optimize the dispersion characteristics of silica-based HFs, and report progress in soft-glass HF fabrication which has resulted in fibers with record values of nonlinearity.

A lead silicate holey fiber with /spl gamma/=1860 W/sup -1/km/sup -1/ at 1550 nm

We report the fabrication of lead silicate holey fibers with record nonlinearities of up to 1860 W/sup -1/m/sup -1/ at 1.55 /spl mu/m. Broadband supercontinuum generation is obtained in a dispersion optimized fiber variant at /spl sim/100 pJ pulse energies for 1.06 /spl mu/m pumping.