Fig. 1. (a) Configuration of our AFLF consisting of two 45°-TFGs segmented by a PMF cavity and corresponding polarization state and phase delay evolutions as the light passes through each portion (inset); (b) theoretically calculated and (c) experimentally measured transmission spectra using PMFs with different lengths of 20 cm, 30 cm, 40 cm, 50 cm, and 60 cm; and (d) experimentally measured and theoretically calculated bandwidths of the AFLF as a function of the PMF length.

Fig. 2. Experimental setup of hybrid mode-locked Tm-doped fiber laser based on an AFLF.

Fig. 3. Performances of mode-locked fiber lasers based on the AFLF with an FSR of 20.8 nm: (a) spectra from seed lasers with/without the AFLF, (b) autocorrelation traces corresponding to (a), (c) pulse waveform and sequence on oscilloscope, and (d) RF spectra with scanning range of 50 kHz and 500 MHz (inset).

Fig. 4. (a) Theoretically calculated transmission spectra of the AFLF at different temperatures, (b) theoretically calculated wavelength shift of the AFLF as a function of temperature, (c) experimentally measured spectra at different temperatures, and (d) experimentally measured center wavelength as a function of temperature.