Ultra-short pulse generating in erbium-doped fiber laser cavity with 8-Hydroxyquinolino cadmium chloride hydrate (8-HQCdCl₂H₂O) saturable absorber

In this study, we demonstrate the generation of soliton mode-locked pulses from an erbium-doped fiber laser (EDFL) cavity configured with 8-Hydroxyquinolino cadmium chloride hydrate (8-HQCdCl₂H₂O) based saturable absorber (SA). The thin-film of 8-HQCdCl₂H₂O was prepared by embedding the 8-HQCdCl2H2O into polyvinyl alcohol (PVA). The soliton mode-locked of EDFL was obtained from laser cavities lengths of 33 m, 53 m, and 103 m. These EDFL cavities of 33m, 53 m and 103 m show repetition rate (pulse width) of 5.6 MHz (950 fs), 3.6 MHz(1.02 ps), and 1.9 MHz (1.53 ps), respectively, at maximum input power of 167 mW. The presence of Kelly sidebands in optical spectrum was obvious with of EDFL cavity 33 m. This indicates that the pulse operation was shifted from stretched pulse to soliton regime with the reduction of cavity length. The soliton mode-locked laser operated at 1563 nm with the shortest pulse width of 950 fs and thus it could be applied in optical communications.