Dynamic Light Storage Based On Controllable Electromagnetically Induced Transparency Effect

Light storage is an important part of all-optical communication,which plays an important role in optical signal processing and chip integration.The key of light storage technology is to greatly slow down the light speed.The most studied optical storage technology is electromagnetically induced transparency(EIT)effect,most of which have delay-bandwidth limitation,usually in order to obtain a long delay time but form a very narrow EIT peak spectral width,which makes the working bandwidth very small,and then leads to a small delaybandwidth product.Later,people find that dynamic modulation on light storage system can break through the delay bandwidth limit,but the system still has some shortcomings,such as requiring rigorous dynamic-phase-matching condition or ultrahigh-speed periodical refractive index modulation.In order to overcome the difficulty of appeal,a coupled cascaded cavitywaveguide in photonic crystal structure is designed to achieve efficient and controllable light storage system based on dynamic EIT-like effect.The paper theoretically and simulatively study the EIT-like effect of coupled cascaded cavity-waveguide in photonic crystal structure,and analyze the influence of the transmission phase difference,the resonance frequency and the coupling coefficient on the EIT-like effect of the system.On this basis,This paper further theoretically study the physical mechanism of controlled light storage and release based on EITlike effect.Then,FDTD simulation is carried out on the coupled cascaded cavity-waveguide in photonic crystal system with different distance between cavities.In the simulation process,dynamic modulation of cavity refractive index is used to successfully realize the switch between high Q and low Q mode of light storage system,and finally realize efficient controllable light storage and on-demand release.More importantly,the dynamic light storage system breaks through the limitation of delay-bandwidth product,obtaining a delay-bandwidth product of more than 1200,much higher than the traditional static light storage/slow light system(less than 2π),and the photon lifetime is more than 4.7 ns.The framework of this paper is as follows: Chapter 1 mainly introduce the concept,use and common preparation methods of photonic crystals,and the research progress of light storage.Chapter 2 introduce the theoretical basis and research methods of photonic crystals.Chapter 3 focus on the design of coupled cascaded cavity-waveguide in photonic crystal structure which can produce EIT-like effect.Chapter 4 discuss how to realize dynamic light storage and break through the restriction of delay-bandwidth product through theoretical analysis and simulation.