All-optical Logic Device Based On Low-dimensional Nanomaterials

Low-dimensional nanomaterials(LDMs)have attracted the wide attention of researchers due to their unique physical and photonic properties since the discovery of graphene.At the same time,all-optical communication and all-optical signal processing play an important role in all-optical systems because they avoid the conversion between optical and electrical signals.All-optical logic devices based on the unique optoelectronic properties of low-dimensional nanomaterials to achieve related functions have become an important research direction.This thesis mainly studies all-optical logic devices based on the thermo-optic effect of low-dimensional nanomaterials.In this thesis,the carbon nanotube-polyvinyl alcohol(CNT-PVA)thin film is firstly prepared by liquid phase exfoliation method,and its physical characteristics,especially optical characteristics were characterized.Then the thermo-optical effect of CNT-PVA film was used to achieve thermo-optical all-optical inversion device.The modulation signal output by this all-optical logic device has fast rising edges(44?s)and falling edges(55?s),and has a long-term stable modulation signal output and ?7k Hz response bandwidth.Finally,the characteristics loss dependent on pump power and laser threshold for damage resistance of CNT material were studied.In addition,in order to further explore the capabilities of low-dimensional nanomaterials in all-optical signal processing,we have studied another low-dimensional nanomaterial,Boron,which exhibits polymorphism in low-dimensional structures and therefore has richer Photoelectric characteristics.We use materials Boron deposition tapered fiber and Boron-PVA thin film to couple the fiber system.Based on the thermo-optic effect of the material,we can achieve a full optical phase shift of up to 8? when the pump power is 600 m W.Device,all-optical switches with fast rising edges(0.48ms)and falling edges(0.69ms),and logic gates capable of performing logical operations on the NOT and AND gates.This experiment further validates the capabilities of low-dimensional nanomaterials in all-optical signal processing.Finally,it summarizes the innovations in the main research content of this thesis,and puts forward the research work that can continue to explore and improve in subsequent experiments.