| The band structure of two-dimensional photonic crystals enables them to modulate optical waves at the subwavelength scale,which has attracted much attention in the field of micro/nano optical devices.The lattice arrangement,lattice period,size of unit cell,occupation ratio and refractive index of nano structures in real space are closely related to the energy band structure of reciprocal space,whose abundant degrees of freedom bring great advantages and development prospect for optical mode modulation.Surface plasmons of metal possess localized field enhancement as well as the ability to break the optical diffraction limit,commonly applied to investigate optical information transmission and the enhancement of light-matter interactions at nanoscale.However,its application is limited by the strong ohmic loss of metals in the surface plasmons system and the inability to radiate into free space due to phase mismatch when propagating at the interface between metal and medium.When the periodic structure of a two-dimensional photonic crystal is combined with surface plasmons system,these defects can be compensated,providing phase matching and suppressing losses,resulting in a high quality resonance,namely surface lattice resonance(SLR).This resonance mode with narrow linewidth and high intensity greatly enhances the efficiency of light-matter interaction and shows great promise in the fields of fluorescence emission enhancement,biosensing detection and optical communication.Based on a metallic photonic crystal structure with a period of 400 nm,this thesis analyzes and modulates the interaction between its energy band structure and the luminescence of the fluorescent dye rhodamine 6G(R6G)on a hexagonal lattice arrangement of Ag nanohole arrays and a honeycomb lattice arrangement of Al nano cone arrays,respectively.Amplified spontaneous emission(ASE)with directional and polarization dependence was achieved,and the properties were investigated based on the information of band structure and SLR in momentum space.The main studies in this thesis are as follows:(1)The propagation path model is constructed based on the conversion between real space and reciprocal space.The band structure and spectra of lattices are simulated and analyzed by using the propagation path model and finite-difference time-domain(FDTD)method.The properties of band sturcture and SLR of hexagonal/honeycomb lattice photonic crystals are systematically studied.(2)A composite structure of hexagonal Ag nanohole array and R6 G was prepared by anodization and physical vapor deposition.ASE based on periodically modulated Bloch surface plasmon polarition(Bloch-SPP)was realized,and the directionality and polarization dependence of the emitted light were investigated.With the change of emission direction and polarization,a transition of photoluminescence intensity can be realized simultaneously,which has good prospects for applications in optical amplifier,optical switch and integrated photonic device.(3)Based on SLR of honeycomb Al nano cone array to realize ASE of R6 G,a momentum space band structure imaging system is established to reveal the optical properties of band structure and SLR in reciprocal space.The principles are explored that the luminescence signal is regulated by light parameters,providing an important reference value for the study of optical wave modulation and light-matter interaction in micro/nano structures. |
