A multiwavelength fiber ring-laser employing a pair of silica-based arrayed-waveguide-gratings

A multiwavelength fiber ring-laser employing a pair of silica-based arrayed-waveguide-gratings (AWG's) is proposed to easily implement a stable multiwavelength operation for a variety of research needs. A fixed multiwavelength operation is available when the free-spectral-range (FSR) of the AWG's is wide enough to cover the gain bandwidth of deployed erbium-doped fiber amplifiers (EDFA's). A tunable multiwavelength operation is also available when the FSR is narrower than the gain bandwidth. 15 channels with 1.6-nm spacing in the fix type, and five channels with about 40-nm discretely tunable range at 1.4-nm spacing in the tunable type and almost 50-dB signal to amplified spontaneous emission (ASE) ratio in both types are demonstrated