The EIT-like Effect And Sensing Characteristics Of Optical Microcavities Based On Bragg Grating

The micro-ring resonator based on SOI structure has the advantages of compact structure,high Q-value and high sensitivity,which has attracted wide attention of researchers.The production process of the microring resonator is compatible with Complementary Metal Oxide Semiconductor(CMOS)technology,enabling large-scale integration and mass production.Therefore,microring resonators are a fundamental component in silicon photonic devices and are widely used in research fields such as filters,sensors,buffers,and optical switches.The Bragg grating has a periodic structure,and the refractive index and waveguide mode of the system are modulated by a gear type waveguide structure.Therefore,this paper will use the silicon-based microring resonator and Bragg grating as the basic unit,using transmission matrix method and effective refractive index method to analyze the transmission spectrum characteristics of different structural systems,and verify the results by FDTD method simulation.The main contents include:In the first chapter,the basic structure and classification of microring resonators are introduced.The development history and basic parameters of microring resonators are briefly reviewed.The SOI structure is an important waveguide structure in silicon photonics and can provide strong power field limiting capabilities.The electromagnetic-induced transparency phenomenon in coupled microring resonance and its application in integrated photonic devices are described.In the second chapter,the transfer matrix method(TMM)and the finite difference time domain(FDTD)method are introduced to analyze the microring resonator.The transmission equation of the microring resonator is solved according to the transfer matrix method,and the transmission spectrum of the different output ports of the microring resonator is obtained by numerical simulation.The simulation software is used to perform FDTD simulation on the microring resonator to obtain the transmission spectrum curve of the system.In the third chapter,the transmission characteristics of the adjustable dual-coupling microring resonator are analyzed.The transmission equation of the system is derived theoretically.The electromagnetically induced transparent spectrum of the dual-coupled microring resonator is given by numerical simulation.The electromagnetic-induced transparency effect is a phenomenon of mode splitting caused by light wave interference.By changing the spacing of the feedback bend coupling regions,electromagnetic-induced transparency spectra of different coupling types are obtained.With the increase of the feedback arm coupling region,the coupling state of the microring resonator has experienced three states of over-coupling,critical coupling and under-coupling.The power field distribution corresponds to different coupling types of the system,and the theoreticalresults are verified by FDTD simulation.In the fourth chapter,we propose a silicon-based slot phase-shifted Bragg grating coupled microring resonator,which is numerically simulated according to the transmission matrix of the system,and the power field distribution of the system at different wavelengths is given.The sensing characteristics of the coupled system in different Na Cl concentrations of solution were analyzed and compared with some similar silicon-based systems.In the fifth chapter,the working principle of the grating-microring-coupled resonator is analyzed.The grating has a certain filtering effect on the spectrum of the microring resonator,thus realizing optical sensing without FSR limitation.The numerical simulation of the transmission matrix of the system is carried out,and the distribution of the power field at resonant wavelengths is given.The sensing characteristics of the coupled system in different concentrations of solution were analyzed.The last chapter is the conclusion of this paper,and the prospect of the research of microring resonator and Bragg gratings.