In this paper, a WSe film prepared by chemical vapor deposition (CVD) is transferred onto a tapered fiber, and a WSe saturable absorber (SA) is fabricated. In order to measure the third-order optical nonlinearity of the WSe, the Z-scan technique is applied. The modulation depth of the WSe SA is measured as being 21.89%. Taking advantage of the remarkable nonlinear absorption characteristic of the WSe SA, a mode-locked erbium-doped fiber laser is demonstrated at 1557.4 nm with a bandwidth of 25.8 nm and signal to noise ratio of 96 dB. To the best of our knowledge, the pulse duration of 163.5 fs is confirmed to be the shortest compared with previous mode-locked fiber lasers based on transition-metal dichalcogenides SAs. These results indicate that WSe is a powerful competitor in the application of ultrashort pulse lasers.

Two-dimensional materials have been widely used as optical modulator materials in mode-locked fiber lasers. In terms of the performance of the fiber laser, one with an ultrashort pulse and high stability has great commercial value. Herein, the MoSe grown by the chemical vapor deposition (CVD) method with high modulation depth, quality lattice structure and uniformity is successfully applied in a mode-locked erbium-doped fiber laser. The pulse duration and signal-to-noise ratio of the laser are 207 fs and 85 dB, respectively. The multifarious performance comparisons indicate that the CVD-based MoSe saturable absorber with the tapered fiber structure has unique advantages not only in the generation of ultrashort pulses, but also in the optimization of laser stability.

Due to the remarkable carrier mobility and nonlinear characteristic, MoS 2 is considered to be a powerful competitor as an effective optical modulated material in fiber lasers. In this paper, the MoS 2 films are prepared by the chemical vapor deposition method to guarantee the high quality of the crystal lattice and uniform thickness. The transfer of the films to microfiber and the operation of gold plated films ensure there is no heat-resistant damage and anti-oxidation. The modulation depth of the prepared integrated microfiber-MoS 2 saturable absorber is 11.07%. When the microfiber-MoS 2 saturable absorber is used as a light modulator in the Q-switching fiber laser, the stable pulse train with a pulse duration of 888 ns at 1530.9 nm is obtained. The ultimate output power and pulse energy of output pulses are 18.8 mW and 88 nJ, respectively. The signal-to-noise ratio up to 60 dB indicates the good stability of the laser. This work demonstrates that the MoS 2 saturable absorber prepared by the chemical vapor deposition method can serve as an effective nonlinear control device for the Q-switching fiber laser.

Silver nanowire (AgNW) has become preferred due to its excellent performance in terms of biocompatibility, transparency, heat transfer and conductivity, and thus has been widely used in catalysts, microelectronic devices, sensors, solar cells, etc. Although some related properties of which have aroused great interest, the nonlinear optical properties of AgNW in laser have not been reported so far. In this paper, the nonlinear optical properties of AgNW are explored in Q-switched fiber laser. Additionally, the effects of three different AgNWs on the performance of corresponding Q-switched lasers are investigated. Results show that the concentration, saturation intensity, insertion loss and modulation depth of AgNW have great influence on the performance of lasers. Moreover, compared with similar SA-based lasers, the AgNW-based laser implemented has bright application prospects in the generation of ultrashort pulses.

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