Carlos De Barros

Suppression of discrete cladding mode resonances in fibre slanted Bragg gratings for gain equalisation

In a slanted Bragg grating, coupling between the fundamental guided mode and the counterpropagative cladding modes result in discrete resonances in the transmission spectrum. These resonances are a drawback when Slanted Bragg Gratings are used for gain flattening of fibres amplifiers. A new method based on a chemical etching of the cladding is proposed leading to an overlap of the resonances and a reduction of the amplitude of the modulation. This method can be applied for any value of photo induced modulation amplitude in the SBG.

Tapered slanted Bragg grating for low insertion loss gain equalizing filter

Here is presented a solution to decrease insertion loss of slanted grating gain equalizing filter, written in fiber with specific photosensitivity profiles.

Dynamically tunable long period grating using two outer gels

We report a new principle to independently tune the wavelength and the transmission of a UV-photowritten Long Period Grating. This principle is based on a variable partial immersion of the grating with two optimized outer gels.

Suppression of discrete cladding mode coupling in fibre slanted Bragg grating spectrum

Slanted Bragg gratings (SBG) have been written in standard telecommunication fibres. Four different methods were studied in order to suppress the peaks induced by discrete cladding mode coupling in SBGs without the use of specific surrounding mediums.