Interferometric fibre grating characterization

The authors have demonstrated an interferometric technique capable of measuring the dispersion of fibre gratings. They have used it to study chirped fibre gratings for dispersion compensation purposes. They have found that, by applying a temperature gradient of 2.7°C/mm to a 2 cm long grating, they can create a negative dispersion capable of compensating the dispersion of about 33 km of standard telecom fibre. The limitations of the interferometric set-up are the polarization sensitivity of the fibre interferometer, wavelength resolution and stability of the laser sources, temperature related phase drifts, and spurious reflections in splices and other parts of the interferometer. Although they degrade the measurements, they do not jeopardize or mislead the interpretation of the results. The authors have found that their results are very repeatable and in good agreement with the theory