Stable multiwavelength erbium-doped fibre laser using intensity-dependent loss mechanism with short cavity length

A simple and stable multiwavelength fibre laser using an intensity-dependent-loss mechanism with a short cavity length is demonstrated. By employing a semiconductor saturable absorber mirror in the cavity to passively modelock the lasing wavelengths, the nonlinear polarisation rotation-induced intensity-dependent-loss is greatly enhanced, which can be used to suppress the mode competition. In the experiment, up to 10 wavelength stable lasing lines in a 3 dB bandwidth with 0.8 nm channel spacing were obtained and the maximum power fluctuation was 0.98 dB.