Saturable Absorbers Based On New 2D Materials For Mode-locking Fiber Lasers

Ultrashort pulsed lasers have numbers of merits such as high peak power,high pulse energy and low thermal effect,so they have been possessed broad application prospects.In the recent years,many emerging 2D-materials have proven as ideal saturable absorbers and applied into short pulses generation with high performance.This thesis mainly discussed optical properties of three kinds of 2D-materials and their application performance in fiber pulsed lasers:1.By a simple optically driven deposition method,black phosphorus(BP)with a thickness of 25 nm was deposited onto the fiber end facet as an effective saturable absorber.Common fabrication methods of BP saturable absorbers are very complex,not suitable for practical large-scale production and hard to prepare the samples with same size and thickness.The introduction of optically driven deposition method as a easy and cheap method solved the fabrication problem.Then we applied the BP saturable absorber into the 1.5 ?m fiber laser and generate stable mode-locking pulses.2.Nonlinear optical properties and mode-locking performance of 2D CH3NH3PbI3 perovskite nanosheets were firstly investigated.It was found that 2D perovskite nanosheets have stronger saturable absorption properties,larger modulation depth and lower saturation intensity comparing with their bulk counterparts.Using an all dry transfer method,we constructed a new type of saturable absorber device based on single piece 2D perovskite nanosheet.Stable soliton state mode-locking was achieved and ultrafast picosecond pulses were generated at 1064 nm.This work paves the way for ultrafast photonic and optoelectronic applications based on 2D perovskites.3.We investigated the nonlinear optical properties of CH3NH3SnI3 perovskite microsheets and grown the samples on the D-shaped fiber directly to fabricate the saturable absorber.The using of D-shaped fiber enhanced the the interaction between light and matter.Then we applied the saturable absorber into the 1060 nm fiber laser and generate the mode-locking pulses.