Over 100 mW Stable Low-Noise Single-Frequency Ring-Cavity Fiber Laser Based on a Saturable Absorber of Bi/Er/Yb Co-Doped Silica Fiber

Two kinds of Yb-doped fibers were fabricated, namely, Yb: YAG crystal-derived silica fibers (YCDSFs) with a gain coefficient of 6.0 dB/cm, and Bi/Er/Yb co-doped silica fibers having a Yb concentration of 0.13
$ \times $
10
²⁶
ions/m
³
. Based on these fibers, a ring-cavity single-frequency fiber laser (SFFL) has been constructed, in which the YCDSF was used as a gain medium and the Bi/Er/Yb co-doped fiber acted as a saturable absorber. It has been demonstrated that the SFFL had an over 100 mW output at 1030 nm, a slope-efficiency of up to 18.3%, and an optical signal-to-noise ratio of over 63 dB. The fluctuation of the output power of the laser was less than 0.65% of 103.5 mW within 10 hrs and no mode-hopping was observed for 5 hrs. The SFFL had a linewidth <7.5 kHz at the maximum output power, and the measured relative intensity noise was lower than −142 dB/Hz at the frequency above 1.0 MHz. The results indicate that the ring-cavity SFFL built could be used as a laser source for applications in high-power fiber laser and high-precision optical fiber sensing and detection.