Study On High Quality Factor Resonance Mode And Its Coupling Characteristics Based On Multilayer Dielectric Composite Structure

The high quality-factor(high-Q)coupled resonators are the cornerstones for building various high-performance optoelectronic devices including filtering,sensing,detection,nano-laser,light-emitting devices.The high quality factor resonance mode characterizes ultra-high spatial confinement,frequency selectivity as well as long photonic lifetime,which can substantially enhance the light-matter interaction.Nowadays,the strategies for achieving the high-Q optical modes mainly includes surface plasmon polariton(SPP)resonance,surface lattice resonance,Fano resonance and guided mode resonance,etc.Very recently,high-Q resonance modes based on topological photonic states and bound states in the continuum have garnered special interest.Due to its extraordinary robustness to the defects in combination with the ultra-high quality factor,these unique optical resonance modes promises potential applications in optical filtering,sensing,photodetection,optical information storage as well as nano-light emitting devices.Based on the numerical simulation and theoretical analysis,the topological photonic states in the heterostructure of one-dimensional photonic crystals and bound states in the continuum in the composite sub-gratings has been systematically studied.The main contents are listed in the following:(1)Strong coupling of topological photonic state(TPS)and Tamm plasmon polaritons(TPPs)has been theoretically investigated in a graphene embedded onedimensional topological photonic crystal(TPC)/Ag regime in visible range.It is shown that the strong interaction of a TPS at the TPC hetero-interface and TPP at the Ag surface enables a large Rabi splitting up to 96.8 me V with a dual-narrow-band perfect absorption.A spectral linewidth of the hybrid mode can be 0.3 nm with a Q factor of 1078.The numerical results also reveal that mode coupling can be either tuned by adjusting the geometric parameters or actively controlled by the incident angle,offering a remarkable polarization-independent strong light-matter interaction.The coupled mode theory is employed to explain the strong TPS-TPP coupling.The polarization-independent and controllable strong mode coupling with a dual-narrow-band perfect absorption in this simple lamellar geometry offers new possibilities for developing various on-chip optical detection,sensing,filtering,and light-emitting devices.(2)An all-dielectric sub-grating resonant structure has been proposed and designed to obtain the high-Q guided resonance modes.By breaking the symmetry of the three grating structure,a bound states in the continuum(BIC)is realized in the resonant structure.Using the quasi-bound states in the continuum,a perfect reflection filtering effect with high quality factor is achieved in the mid-infrared band,whose line width is less than ?? = 0.3 nm near the wavelength of 3.7 microns.The simulation results indicate that the guided-mode resonance wavelength and quality factor of the quasi-bound states in the continuum grating can be flexibly adjusted through changing geometric parameters and incident angle of light.Our findings open a new way for developing the filtering,high-sensitivity sensing and detection,and light-emitting devices.