Abstract

Efficient wavelength conversion between telecommunication bands at 0.8 and 1.55 μm would allow these transparency windows to be more fully utilized in fibre network. Parametric wavelength converter based on four-wave mixing (FWM) in a silica microstructure fibre is very promising for solving this problem. The desired dispersion shape with the zero dispersion wavelength (ZDW) in the region of 1-1.1 μm is readily achieved with this fibre [1]. However, the nonlinear coefficient is relatively small for the pure silica fibre with the required dispersion characteristic [2]. With the goal of enhancing the FWM efficiency, we fabricated and studied the microstructure fibre with a germanosilicate core. Our fibre has a technologically simple design of 2 rings of air holes in hexagonal symmetry with the hole diameter of 2.7 μm and the pitch of 3.1 μm. The center of the core region with the diameter of 1.7 μm was doped with 24 mol % GeO₂. A dispersion characteristic with ZDW at 1.09 μm allowed us to achieve phase matched anti-Stokes and Stokes wavelengths in the region of 0.8 and 1.55 μm, respectively, upon pumping at 1.064 μm. The measured loss did not exceed 20-30 dB/km in the bands of 0.8 and 1.55 μm. The evaluated nonlinear coefficient was 40 (W km)^-1 at λ= 1.064 μm (7 times higher than for a fibre with a pure silica core and the same dispersion characteristic [2]).

© 2009 IEEE