Characteristic Analysis And Applied Research On Two-Dimensional Photonic Crystal Microcavity

With the rapid development of electronic information technology,people have high requirements on miniaturization of integrated circuits,information transmission and information processing speed.Because there's an interaction between electrons and electrons.So the performance of semiconductor devices is limited in the process of miniaturization,resulting in large energy loss and slow information transmission.In order to seek a breakthrough,the study of optical information technology has entered the field of human vision.As a new type of optical material,photonic crystal has the advantages of high integration,low power consumption and high precision when it is used to make optical devices.Based on the perfect two-dimensional photonic crystal and photonic crystal microcavity,this thesis analyzes the band gap characteristics,optical field distribution characteristics and optical local characteristics by using plane-wave expansion method and time-domain finite difference method.On this basis,the coupling characteristics and the light controlling principle of two-dimensional photonic crystal waveguide and microcavity are studied.Based on the characteristics of magnetic photonic crystal permeability changing with external magnetic field and the optical transmission characteristics of mach-zehnder interferometer,a filter with optical switch function and an all-optical logic gate with multiple logic functions are designed.Specifically,it includes the following contents:(1)Study on the optical control characteristics of two-dimensional photonic crystal microcavity and waveguide.Firstly,the effects of lattice structure,filling ratio and dielectric constant on the band gap of two-dimensional photonic crystal are analyzed in order to study the light-controlling characteristics of the photonic crystal waveguide and microcavity.Then,on the basis of two-dimensional photonic crystal of triangular plate air hole,the most basic structure of point defect microcavity is designed,and the influence of central air hole radius of microcavity and dielectric constant of dielectric plate on the performance of microcavity is analyzed.The results show that when the dielectric constant is 11.4 and there is no air hole in the defect center,the quality factor Q is 3364.The field intensity in the microcavity is the largest and the performance is the best.Finally,the characteristics of photonic crystal waveguide are analyzed.On the basis of coupled mode theory,the coupling characteristics and light controlling principle of two-dimensional photonic crystal waveguide and microcavity are derived in detail.It provides the foundation and premise for the design of the following filters and logic gates.(2)Design and performance analysis of two-dimensional photonic crystal THz filter.Firstly,the influence of external magnetic field on the permeability of magnetic materials was analyzed,and the band gap of magnetic photonic crystals in different magnetic field was calculated.The results show that the band gaps of photonic crystals vary with the magnetic field intensity.Then,magneto-photonic crystals with specific dielectric column radius are introduced into two microcavities with different structures,and the corresponding THz filter structure is designed.The filter characteristics of THz filter are analyzed,and the influence of the radius of coupling medium column on the filter performance is studied.So the optimal radius of coupling medium column in two THz filter structures is obtained.Finally,two kinds of THz filter structures are combined to make a multi-channel two-dimensional photonic crystal THz filter.The performance of the filter is analyzed.The results show that when the magnetic field is not applied,the filter can filter the light wave with the wavelength of 83.33 um and 92.59 um,and the transmittance is 0.91 and 0.89.And the filter has high channel isolation and low insertion loss.When the magnetic field is applied,the transmittance of light waves with wavelength of 83.33 um and 92.59 um at the output port is only 0.15 and 0.14.So the filter realizes the function of optical switch,and has obvious switching effect and short response time.(3)Design and performance analysis of all-optical logic gates.In this thesis,the light controlling characteristic and sensing principle of mach-zehnder interferometer are analyzed,and the coupling relationship between mach-zehnder interferometer and micro-ring resonator is analyzed.An all-optical logic gate based on two-dimensional photonic crystal MZI microcavity is designed.By changing the phase difference between the control end and the input end and the input end of the light wave,different logic functions can be realized.The results show that the logic functions of logic gates can be: or logic,same or different logic,or different logic.And each logic gate has a high extinction ratio of 31.802 dB,25.670 dB and 27.701 dB,respectively.The response time of the logic gate is short,the size is small,and the response time is only 0.151 ps.