Abstract
In this contribution we compare the thermal stability of type I and type IIa gratings written in germanosilicate fibers. We study and compare their central wavelengths drifts and variations of the maximum reflectivity with temperature. Also, two other important factors, the bandwidth and group delay characteristics are characterized, compared, and the differences justified, based on the gratings physical structure.

Abstract
Fiber Bragg grating (FBG) written in normal and reduced diameter high birefringence (HiBi) optical fibers have been studied. Chemical etching is used to reduce the fiber diameter while the optical properties of the FBG spectrum are measured. The obtained results agree qualitatively with the stress enhanced chemical etching. They also permit to determine the birefringence of the fiber as a function of the diameter. Optical characterization of the FBG under transversal strain and temperature is performed. The obtained results permit the simultaneous measurement of those parameters with a HiBi FBG sensor.

Abstract
In this paper we report the implementation of fiber Bragg gratings with variable negative mean refractive index perturbation, in a highly germanium-doped fiber, resultant from a type IIa exposition regime. The obtained grating presents a favorable group delay characteristic for dispersion compensation applications with reduced bandwidth.

Abstract
We propose and demonstrate an architecture of a 2 x 2 port optical cross-connect (OXC) using tuneable fibre Bragg gratings and optical circulators. The proposed OXC is scalable to N x N ports owing to the cascadability of individual routing modules, which perform routing of specific wavelength channels. The performance of the cross-connect is also experimentally evaluated.

Abstract
In this paper, we present a continuous-wave tunable fibre ring laser operating in the L-band. A bi-directional pumped L-band erbium-doped fibre amplifier provides gain to the loop. Tunability is achieved by bending a single-mode fibre taper using a micrometer drive, controlling in this way the spectral cavity losses. Laser emission is achieved between 1587 and 1606 nm, and low variation of the output laser power is observed over all the tuning range.

Abstract
A new scheme based on four-wave mixing is presented using a ring erbium-doped fibre laser and tuneable fibre Bragg gratings that can effectively perform wavelength conversion in a wide wavelength range. An application of this wavelength-conversion architecture to optical communications is also presented.