Tunable wavelength spacing multi-wavelength ring laser using programmable DGD module as intra-cavity filter

A multi-wavelength fibre laser whose channel spacing can be dynamically and continuously tuned is demonstrated experimentally. A novel programmable magneto-optic-based DGD module is used as the intra-cavity optical filter to control the wavelength spacing. Channel spacing tunable from 0.4 to 1.6 nm is achieved.