Highly uniform room-temperature multiwavelength unidirectional erbium-doped fibre ring laser without isolators

A high-performance multiwavelength erbium-doped fibre ring laser with sine phase modulator to obtain stable 30 lasing lines in power difference of less than 2 dB is demonstrated. In addition, non-reciprocal loss caused by the proposed cavity structure ensures unidirectional operation when lasing even without optical isolators.