Research On Photonic Crystal Theory And Device Design And Quantum Entanglement

With the rapid increase of information requirement for human society,the information industry with electronic as the information carrier,has gradually failed to meet people's information demand,which promote the information technology to develop forward.At present,the field of photonics and quantum communication has become two hot research fields.Therefore,photonic crystals and photonic crystal waveguides that can control photon behavior,can make all kinds of excellent property optical devices,it has become an important research direction in the photonics field,and became one of the most popular research field.The quantum information science,which combines quantum mechanics with information science,has great theoretical significance and applicable value,and has been made important progress in both theory and experiment.Among them,the quantum entanglement is the basis and key of quantum communication and quantum computing.So,the generation mechanism and experimental preparation of quantum entanglement has became one of the most popular research subjects in physics.This paper introduces and summarizes the theoretical research and optical device design of new photonic crystals,and the study of quantum entanglement theory and mechanism,,which I have done during the Ph D period.The main contents are as follows:(1)In this paper,the structure and theoretical analysis of a new one-dimensional function photonic crystal are studied.On this basis,we have designed the optical triode with one dimensional function photonic crystal,and given the factors affecting the triode magnification times.A new type of two-dimensional function photonic crystal is proposed also,and given the Fourier transform form of the dielectric constant.The band gap structure of TE and TM waves is calculated using the plane wave expansion method.The study found when the parameters change,the band gaps number,width,location,absolute band gaps and semi-Dirac points all should be changed.The band gap structure of two-dimensional function photonic crystal has adjustability,the required gap structure photonic crystal can be designed conveniently by two-dimensional function photonic crystal.(2)In this paper,the variable frequency and variable time one-dimensional photonic crystal have been proposed.The transmission characteristics and electric field distribution of variable frequency and variable time photonic crystal were calculated respectively,and obtained some valuable conclusions.The band gap structure of variable frequency one-dimensional photonic crystal has adjustability,the transmission characteristics of the variable time one-dimensional photonic crystal can change periodically,which can be used to make high precision optical switch.(3)In this paper,we have proposed a new quantum theory method to study the quantum transmission characteristics of photonic crystals,and given the quantum transmission matrix,quantum reflection coefficient and quantum transmission coefficient.The quantum transmission characteristics of one-dimensional photonic crystals with and without defects are calculated and compared with classical transmission matrix methods.We found that when the incident light was vertical,the results of the two methods were identical,when the incident light was not vertical,the results of the two methods were slightly different.With the incidence angle increase,the difference also increase,which is the quantum effect.(4)In this paper,the one-dimensional composite structure photonic crystal of series,parallel,positive feedback and negative feedback were proposed,and the transmissivity of this composite structure photonic crystal were calculated.We found that the series structure photonic crystals can obtain more wider band structure,the band gap structure of the parallel structure photonic crystals has adjustability,the positive and negative feedback structure photonic crystalcan realize the amplification of light and multi-channel optical filter,and can be designed as the photonic crystal laser.the logical AND gate and the logical OR gate were designed based on the composite structure photonic crystal of series and parallel.With two photonic crystals in series,it can realize the logic AND operation,with two photonic crystals in parallel,it can realize the logic OR operation.The design of the logic operation will be widely applied in optical communication,optical computing and so on.(5)In this paper,we have applied the J-C mode to study the evolution characteristics between entanglement and time,when atoms and light fields in linear and nonlinear media in the multiple photon transitions(N=1,2,3,4,5,6).The relationship between the entanglement of the atoms and the optical field and the initial state parameters,the quantum discord quantity,initial photon numbers,the transition photon numbers and nonlinear coupling constant were given.Some valuable results are obtained through numerical calculation,which will have the theoretical significance and practical application value in quantum computation and quantum remote communication.(6)In this paper,we have studied the entanglement dynamics mechanism between electron and electron,the photon and the photon,and given the spin entangled state of two electrons,three electrons and two photons respectively.On this basis,we can further think that quantum entanglement between arbitrary two or more subsystems comes from their direct or indirect interaction.When the interaction between subsystems is changed,the quantum entanglement between them should be affected.By changing the external conditions,the generation and evolution of entangled states can be controlled and adjusted.The theory will play an important role in quantum information.