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(44μs)and falling edges(55μs),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 8π 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.