METHOD AND APPARATUS FOR ESTIMATING CHROMATIC DISPERSION IN FIBRE BRAGG GRATINGS

摘要

The present invention provides a method and apparatus for obtaining a measur e of the chromatic dispersion of a fibre bragg grating (40), the method comprising: disposing the grating in a reflection (34) arm of an interferometer; inputting probe laser light into the interferometer; stepping the wavelength of the light across t he reflection bandwidth of the grating, while at each step modulating the wavelength by a wavelength modulation less than the size of t he respective step, and thereby producing a resulting phase modulation; and demodulating the phase modulation and determining therefrom a measure of the chromatic dispersion.