Tunable dual-wavelength ytterbium-doped fiber ring laser based on a Sagnac interferometer

A tunable dual-wavelength ytterbium-doped fiber ring laser based on Sagnac interferometer is proposed and experimentally demonstrated. Due to a broad gain bandwidth of ytterbium-doped fiber, a tuning range of 17.9 nm for single-wavelength lasing output and 8.4 nm for dual-wavelength lasing have been achieved with side-mode suppression ratio higher than 38 dB. In addition, experimental results indicate that the lasing output has favorable wavelength and power stability with the maximum wavelength shift and the peak power fluctuation less than 0.06 nm and 0.94 dB, respectively. Such a wide tunable ytterbium-doped fiber ring laser around the wavelength of 1 µm with simple structure has potential applications in metrology, medical treatments or laser cooling, where the laser wavelength need adjusted accurately.