Nonlinear Enhacement And Laser Based On MaPbBr₃ Metagrating

Light matter interaction is very important for spectroscopy,sensing,quantum information processing and laser.Local field enhanced electromagnetic field interacting with bound electrons and free electrons realizes a large number of light matter interaction phenomena which can not be observed previously.Nonlinear optics describes intensity-dependent optical phenomena promoted by light matter interaction.Therefore,how to enhance light matter interaction becomes a key problem.The progress of all dielectric nanophotonics has led to the development of high-efficiency flat-plate photonic devices,and the performance of these devices is up to or even better than that of traditional bulk nonlinear crystals.In this thesis,based on the all dielectric metagrating,a series of studies on the light matter interaction are carried out.This thesis focuses on the light matter interaction,starting from enhancing nonlinear response by Mie scattering,then studying the enhancement of grating waveguide resonator,finally realizing the emission laser with the help of the bound in the continuum state from studying grating waveguide resonator.This thesis paves a way for studying the foundation of light matter interaction.In this thesis,Mie scattering metagrating enhancing nonlinear response are studied.By analyzing the analytical solution of Mie scattering theory,considering the lowest order scattering phase,the solution space of structure parameters is obtained.The localized electric field is regulated by the grating controlled by Mie scattering resonance,and three-photon fluorescence intensity is enhanced by 60 times.The perovskite dielectric grating structure enhanced by Mie scattering magnetic dipole resonance is designed by using Mie scattering theory.It is verified that the local enhancement of electromagnetic field intensity can be realized in the perovskite grating,and the enhancement of three-photon fluorescence can be realized based on this enhancement.This can provide new ideas and methods for the design and application of display and encryption technology based on nonlinear optics.In this thesis,a perovskite metagrating with a grating waveguide resonator structure is designed and fabricated.Electromagnetic field is mainly localized in the perovskite waveguide layer and the structure is used to improve the electromagnetic field enhancement factor.Six orders of magnitude of two-photon fluorescence enhancement are achieved.The threshold energy of two-photon stimulated radiation can be equal to that of single-photon excited radiation.The threshold of two-photon stimulated emission is only 3 times that of single-photon excited stimulated emission.Based on the resonance of grating waveguide,a metagrating with stronger enhancement factor of electromagnetic field is designed,and interaction distance contact with gain medium is increased at the same time.The extremely obvious enhancement effect is achieved,which is expected to improve the study of nonlinear light matter interaction.This paves a new way for the application of metasurface optical devices in the field of light material interaction.In this thesis,a kind of perovskite laser based on bound in the continuum based on grating waveguide resonator structure is designed.By using bound state in the continuum mode,together with etchless fabrication process,based on the high gain medium perovskite,the laser with quality factor up to 3×10~3,controllable wavelength and high repeatability is realized.It opens up a new way for developing laser devices on metasurfaces and the study of basic physical laws of detection.