Experimental observation of reverse wavelength self-sweeping effect is reported in a bidirectional ytterbium-doped fiber ring laser. The wavelength self-sweeping regime - that a spontaneous, periodical, stable - can be obtained by the dynamical induced grating formed in an active medium due to the spatial hole burning. In this work, the reverse self- sweeping effect operates, for the first time, to the best of our knowledge, in 1.037 μm wavelength region. Besides, the fiber laser can generate a self-pulse signal and reverse wavelength self-sweeping with an average rate of 0.38 nm/s in the largest coverage of 2.75 nm. The self-pulse signal that modulated by inter-mode beating can be observed and the microsecond pulse train envelopes are in the range of 116-128 kHz.
The current state of single frequency fiber laser technology based on different saturable absorbers (SA) is reviewed. The proposed and experimental fiber lasers used ytterbium-doped fiber (YDF) as the gain medium and the mode selection is done by Sagnac interferometer loop mirror filter (LMF) incorporated SA. In this paper, we review the experiment principle and process of SF fiber lasers utilizing different function materials as the SA, including the fabrication, features of the two-dimensional (2-D) materials (graphene and molybdenum disulfide film) SA. The SA is like a narrowband filter to ensure the longitudinal mode operation. Finally, we systematically analysis and compare the experimental results based on different SA.