We demonstrated an all-fiber Er-doped Mamyshev oscillator with short pulse duration and high peak power. Through the dispersion management technique and accumulation of sufficient nonlinear phase shift, stable pulses with repetition rate of 6.55 MHz, 20-dB spectral bandwidth of 78.2 nm, pulse duration of 72 fs and peak power of 86 kW were achieved directly without external compression. Simulations have been performed to show the direct generation of ultrafast laser pulse from the Mamyshev oscillator based on the extended nonlinear Schrdinger equation. To the best of our knowledge, this is by far the shortest pulse duration, the highest experimental peak power Er-doped Mamyshev oscillator.

We have synthesized highly monodisperse PbS/CdS quantum dots with bright infrared emissions via a low-temperature shell growth approach. Stable Q-switched and mode-locked ultrashort pulses are generated based on PbS/CdS saturable absorbers.

We numerically study a hybrid mode-locked holmium-doped fiber laser based on the coupled nonlinear Schrödinger equations, by introducing nonlinear polarization rotation and saturable absorber in a same cavity. Maps of mode-locking states related to the intracavity wave-plates are created to evaluate the stability of mode-locking. Nonlinear polarization rotation imposes negative effect of linear absorption and even reverse saturable absorption to the pulses in the hybrid cavity. Saturable absorber compensates the negative effect from nonlinear polarization rotation, then consequently contributes to the stability of single-pulse mode-locking states. The extension of pulse time duration indicates the dynamic synergy between nonlinear polarization rotation and saturable absorber rather than the static combination mechanism of them.

The superhydrophobic surface can change the friction property of the material, reduce the adhesion of the friction interface, and produce a certain slip, thereby reducing the friction coefficient. The laser has high energy, high density, and is especially suitable for the surface treatment of materials. The laser surface texturing is a good way to construct superhydrophobic surfaces. The experiment uses a nanosecond pulse laser to construct the groove texture on the nickel surface. The contact area between the air and the droplets retained on the rough surface is increased, effectively preventing the water droplets from entering the gully of the surface microstructure, reducing the water droplets and the solid surface. The contact area ultimately makes the surface exhibit excellent superhydrophobicity. A superhydrophobic nickel surface having an apparent contact angle of water (ACAW) of 160° and a sliding angle (SA) of less than 10° was prepared. The MM-W1B vertical universal friction and wear tester was used to test the groove texture samples with different depths. The surface texture can capture the wear debris generated by the wear and store the lubricant, which is beneficial to the formation of fluid dynamic pressure lubrication and improve the load. The friction coefficient is reduced from 0.65 of the unprocessed surfaces to 0.25 after the texturing, and the friction performance is greatly improved.

We have synthesized high-quality 2D, quasi-2D and 3D (PEA)₂(CsPbBr₃)_n−1PbBr₄ perovskites. Stable mode-locked ultrashort pulses are generated based on these three saturable absorbers.