Laser wavelength stabilisation using fibre grating

The work presented describes the use of a Bragg fibre grating filter for the stabilisation of a semiconductor laser suitable for dense WDM (DWDM) systems. Two stabilisation techniques are studied. The first uses the peak of the reflected filter passband as the frequency reference point and the second the crossover frequency of the transmitted and reflected filter passbands. In order to access the suitability of the approach for DWDM a typical source wavelength budget has been used as the basis for the study where the channel spacing is assumed to be 200 GHz minimum (1.6 nm). With this channel spacing a total wavelength tolerance of ±0.26 nm is deemed sufficient to ensure system operation