Wavelength-switchable ultra-narrow linewidth fiber laser enabled by a figure-8 compound-ring-cavity filter and a polarization-managed four-channel filter

We propose and demonstrate a high-performance wavelength-switchable erbium-doped fiber laser (EDFL), enabled by figure-8 compound-ring-cavity (F8-CRC) filter for single-longitudinal-mode (SLM) selection polarization-managed four-channel (PM-FCF) defining four lasing wavelengths. introduce novel methodology utilizing signal-flow graph combined with Mason’s rule to analyze CRC in general apply it obtain the important design parameters F8-CRC used this paper. By combining functions of PM-FCF assisted enhanced polarization hole-burning dependent loss, we achieve EDFL fifteen states, including single-, six dual-, tri- one quad-wavelength operations. In particular, all single-wavelength operations are stable SLM oscillation, typically linewidth <600 Hz, RIN ≤−154.58 dB/Hz@≥3 MHz an output power fluctuation ≤±3.45%. addition, dual-wavelength have very similar performances, performance close those operations, superior our previous work others’ significantly. Finally, wavelength-spacing tuning photonic generation tunable microwave signals, successfully signal at 23.10 GHz as demonstration.