Broadband spatial self-phase modulation of black phosphorous.

Spatial self-phase modulation (SSPM) experiments on two-dimensional (2D) black phosphorus (BP) nanoflake suspensions are performed with focused femtosecond pulsed lasers at 350-1160 nm. In the broadband region, the slope of the SSPM ring number versus laser intensity varies from 0.99 to 0.34, which is larger than 0.25 in MoS2. We deduce the portion of the fluid globe (ξ) to be 0.0067, which is a constant independent of laser intensity, when the laser intensity is above 10 W/cm2. The nonlinear refractive index of BP is measured to be ∼10(-5) cm2 W(-1), and the third-order nonlinear susceptibility is χ(3)∼10(-8) esu at multiple wavelengths.

Dynamic self-diffraction in MoS(2) nanoflake solutions.

We observe dynamic self-diffraction in MoS(2) supernatant solutions with laser for the first time, and conduct dynamic data simulation and analysis. Observation results indicate that self-diffraction can be divided in three stages: in the first stage, laser changes from Gauss beam to symmetric diffraction rings because of the force from laser. In the second stage, diffraction rings become asymmetric vertically because of gravity. In the third stage, diffraction rings become asymmetric horizontally, as a result of fine structure of laser. We obtain the dynamic distribution of MoS(2) nanoflake in solution under the effect of laser by dynamic diffraction image simulation.