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The generation of mode-locking pulse train in Erbium-doped fiber laser (EDFL) cavity was demonstrated using Nickel Oxide (NiO) saturable absorber (SA). The NiO compound synthesized via sonochemical method was embedded into poly ethylene oxide (PEO) film through solution casting technique to fabricate the SA film device. A small piece of the SA film was sandwiched between two ferrules in the EDFL cavity. By adding 180[Formula: see text]m single mode fiber (SMF) in the ring cavity, a stable mode-locking pulse train operating at 1558[Formula: see text]nm with a repetition rate of 1.1[Formula: see text]MHz was achieved. At 197.5[Formula: see text]mW pump power, the proposed mode-locked EDFL has output power and pulse energy of 3.35[Formula: see text]mW and 3.36[Formula: see text]nJ, respectively. This study may well be the first demonstration of mode-locked EDFL using NiO-based SA. The result indicates that NiO is the promising material for ultrafast photonic applications.

We demonstrated an all-fiber mode-locked Thulium–Holmium co-doped fiber laser (THDFL) based on molybdenum disulfide (MoS2) tape saturable absorber. The THDFL generates a mode-locked pulse in anomalous regime at 1,979[Formula: see text]nm using 5[Formula: see text]m long Thulium–Holmium co-doped (THDF) as a gain medium. Through mechanical exfoliation method, the MoS2 was mechanically extracted from a commercial MoS2 crystal by using a clear scotch tape. Through balanced twin-detector measurement, the obtained MoS2 tape has a nonlinear absorption of 10% with 100[Formula: see text]MW/cm2 saturation intensity. Under 775[Formula: see text]mW to 852[Formula: see text]mW pump power, a stable pulse train was obtained at 9.12[Formula: see text]MHz repetition rate with a signal-to-noise ratio (SNR) of 45[Formula: see text]dB. The maximum output power and pulse energy were measured about 20[Formula: see text]mW and 2.2[Formula: see text]nJ, respectively. With a 3-dB spectral bandwidth of 2.1[Formula: see text]nm, the minimum possible pulse width was determined as 1.97[Formula: see text]ps.

A switchable soliton mode-locked and multi-wavelength operation in thulium-doped fiber laser (TDFL) is demonstrated based on nonlinear polarization rotation (NPR) technique. The TDFL produces a soliton pulse operating at 1917.66[Formula: see text]nm using a 5[Formula: see text]m long thulium-doped fiber (TDF) as a gain medium as well as nonlinear medium. The solitonic behavior is further identified with two orders of Kelly sidebands in the output spectrum. The mode-locked emission is obtained from threshold pump power of 522–1052[Formula: see text]mW with consistent pulse repetition rate of 14.7[Formula: see text]MHz. Maximum pulse energy is calculated as 0.89[Formula: see text]nJ at pump power of 1052[Formula: see text]mW, whereas the maximum pulse width is estimated to be approximately 1.36[Formula: see text]ps corresponding to sech2 pulse profile. By shifting the polarization orientation, the cavity can change to multi-wavelength operation with signal-to-noise ratio (SNR) higher than 53[Formula: see text]dB. At pump power of 1037[Formula: see text]mW, three stable peak wavelengths are generated with a power fluctuation and constant spacing of [Formula: see text] dB and 7.4[Formula: see text]nm, respectively.

We demonstrate a Q-switched Erbium-doped fiber laser (EDFL) using a molybdenum disulfide (MoS[Formula: see text]-based saturable absorber (SA) as a Q-switcher. The SA is prepared from commercial available MoS2 pristine flakes with final solution concentration of [Formula: see text]0.02[Formula: see text]mg/ml. The Q-switcher is assembled by depositing a dried MoS2 onto a fiber ferule facet before it is matched with another clean ferrule via a connector. By increasing the pump power from 120[Formula: see text]mW to 160[Formula: see text]mW, stable generation of Q-switched EDFL incorporating MoS2 SA has been obtained at 1502[Formula: see text]nm wavelength. The pulse repetition rate also varies from 45.2[Formula: see text]kHz to 66.0[Formula: see text]kHz with pulse width which is increased from 2.73[Formula: see text][Formula: see text]s to 3.19[Formula: see text][Formula: see text]s. At pump power of 160[Formula: see text]mW, we successfully generated the maximum average output power of 0.51[Formula: see text]mW, corresponding to a pulse energy of 7.8[Formula: see text]nJ.