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We experimentally demonstrated a passively Q-switched Nd:YAG laser based on CH3NH3PbI3 perovskite as a saturable absorber.

Group VIB transition metal dichalcogenides (TMDs) have been successfully demonstrated as saturable absorbers (SAs) for pulsed fiber lasers. For the group comprising IVB TMDs, applications in this field remain unexplored. In this work, ZrS2-based SA is prepared by depositing a ZrS2 nanostructured film onto the side surface of a D-shaped fiber. The nonlinear optical properties of the prepared SA are investigated, which had a modulation depth of 3.3% and a saturable intensity of 13.26 MW/cm2. In a pump power range of 144–479 mW, the Er-doped fiber (EDF) laser with ZrS2 can operate in the dual-wavelength Q-switching state. The pulse duration declined from 10.0 μs down to 2.3 μs. The single pulse energy reached 53.0 nJ. The usage of ZrS2 as a SA for pulse generation in fiber lasers is presented for the first time. Compared to the experimental results of dual-wavelength Q-switched fiber lasers with two-dimensional (2D) materials, our laser performance was better. Our work indicates that the group comprising IVB TMD ZrS2 has bright prospects for nonlinear optical applications.

High-performance ultrafast fiber lasers require saturable absorbers (SAs) of high optical damage threshold and high operation stability. Here, the optical properties and application of the WS2/SiO2 SA prepared by the sol–gel method are reported. SiO2 prepared by sol–gel technique has similar properties to fiber in ultrafast fiber lasers, such as mechanical strength, refractive index, optical transmission, and absorption. For the SA device by the sol–gel method combined with WS2 material, not only will the additional scattering loss not be introduced, but also, the damage threshold of the SA device can be effectively increased. Furthermore, SA material is wrapped by SiO2, which insulates the influence of the external environment. Based on the first preparation of the WS2/SiO2 glass SA, stable soliton pulses are obtained in ytterbium-doped fiber lasers (YDFLs) with a pulse width of 58 ps, an average output power of 56.8 mW, and a repetition rate of 19.03 MHz. In addition, a stable mode-locked operation with a pulse width of 325 fs and an output power of 39.6 mW is also achieved in an erbium-doped fiber laser (EDFL). These results demonstrate that the WS2/SiO2 glass prepared by the sol–gel method can significantly increase laser output power and shorten pulse width in the fiber laser, which provides a new opportunity for the traditional preparation method of the SA device.

Abstract As a new member of saturable absorber (SA), molybdenum carbide (Mo2C) has some excellent optical properties. Herein, we report a new type of Mo2C/fluorine mica (FM) SA device. Uniform and compact Mo2C films were deposited on the FM by magnetron sputtering method. In order to increase the laser damage threshold, an additional protective layer of silicon oxide was deposited on the Mo2C. The FM is a single-layer structure of 20 μm, and its high elasticity makes it not easy to fracture. The transmission rate of FM is as high as 90% at near infrared wavelength. FM has better heat dissipation and softening temperature than organic composite materials, so it can withstand higher laser power without being damaged. In this work, Mo2C/FM SA was cut into small pieces and inserted into erbium-doped fiber laser to achieve mode-locked operation. The pulse duration and average output power of the laser pulses were 313 fs and 64.74 mW, respectively. In addition, a 12th-order sub-picosecond harmonic mode-locking was generated. The maximum repetition rate was 321.6 MHz and the shortest pulse duration was 338 fs. The experimental results show that Mo2C/FM SA is a broadband nonlinear optical mode-locker with excellent performance.