Zhiming Liang

Few-layer selenium-doped black phosphorus: synthesis, nonlinear optical properties and ultrafast photonics applications

We reported on the synthesis of high quality bulk selenium (Se)-doped black phosphorus (BP) crystals using a mineralizer assisted gas-phase transformation in a mild growth condition and employed a liquid phase exfoliation approach to obtain few-layer (FL) Se-doped BP nano-sheets from the bulk counterpart. We experimentally found that FL Se-doped BP shows enhanced optical saturable absorption with long term stability, which may originate from selenium doping-induced changes of intrinsic carrier density. Taking advantage of its nonlinear optical property, we designed an optical saturable absorber (SA) device based on FL Se-doped BP, allowing the generation of a femto-second pulse in the fiber laser. Our results not only provide a new strategy in tailoring the nonlinear optical response of BP through element doping, but also suggest that FL Se-doped BP can be developed as a excellent candidate for ultrafast photonics.

Period-Doubling and Quadrupling Bifurcation of Vector Soliton Bunches in a Graphene Mode Locked Fiber Laser

Period-doubling bifurcation and period-quadrupling bifurcation of vector soliton pulses in a graphene mode locked fiber laser is experimentally observed and investigated. Not only single vector soliton but also vector soliton bunches as a unity are found to exhibit period-doubling and period-quadrupling bifurcation. The experimental results suggest that period-doubling and quadrupling bifurcation are intrinsic features of the pulses circulating in a nonlinear ring cavity, which are independent of the properties of the mode-locker in the fiber lasers.