Actively Mode-locked Multiwavelength Fibre Ring Laser Incorporating a Lyot Filter, Hybrid Gain Medium and Birefringence Compensated LiNbO3 Modulator

A lyot filter based actively mode-locked multiwavelength fibre ring laser with a hybrid gain medium, consisting of an SOA and EDFA, is presented. Simultaneous mode-locking of up to 8 wavelength channels at 10 GHz is realised using a LiNbO
₃
based Mach-Zehnder intensity modulator. A wavelength channel spacing of 100 GHz is obtained via appropriate tuning of the Lyot filter length. The effect of modulator birefringence on the performance of the laser spectrum is investigated and a simple method to increase spectral stability is proposed and demonstrated.