Research On Black Phosphorus All-optical Modulation And Wavelength Conversion Based On Micro/nano Fiber

Owing to its unique two-dimensional structure feature and photoelectric properties,two dimensional black phosphorus has received the attention from the researchers since it has been found.It is worth noting that the black phosphorus has an excellent nonlinear coefficient,and it is a kind of promising ultra-compact nonlinear optical medium.Therefore,in this thesis,the black phosphorus-microfiber composite structure is prepared by the method of optical deposition in experiment successfully.This composite structure is a incorporation the nonlinear effect(saturated absorption effect and optical Kerr effect)of black phosphorus and the advantages of micro-fiber,and the composite structure are applied in the all-fiber system to achieve all-optical modulation and wavelength conversion in experiment.Based on saturated absorption effect of black phosphorus-microfiber composite structure,this composite structure can realize all-optical modulation and all-optical thresholding in the full optical fiber system.When black phosphorus-microfiber composite structure applies in all full optical fiber system,this device can not only adjust the on/off state of the signal by controlling the power of the pump,but also be used to improve the signal-to-noise ratio of the signal.The extinction ratio of light modulator is 4.7 and the signal-to-noise ratio of the light pulse signal is improved from 3.54 to 17.5,so the device of thresholder can further improve the quality of all optical modulation.The device can be seamlessly integrated with the full fiber system,and it is expected to be widely used in the future all optical network.In this paper,through combining the black phosphorus with microfiber waveguide,phase modulation and four-wave mixing phenomenon are observed in experiment.The Kerr light switcher device has realized the extinction ratio up to 26 d B,with operating wavelength conversion range more than 18 nm.At the same time,the experimental results show that the black phosphorus of new two-dimensional materials has excellent nonlinear optical effect,and can be used to realize wavelength conversion and the generation of optical signals in communication band of the full optical fiber system.Black phosphorus has great application and development prospect in miniature photoelectric device.