Research On Optical Properties Of Hybrid Lead Halide And Silicon Metasurfaces

Metasurfaces have attracted tremendous research attention in the optics community due to the ultrathin thickness and the super ability to control the optical field.Nowadays,metasurfaces are mainly utilized for three aspects.The first one is phase manipulation.It can be used to realize metalens,beam splitter,vortex beam and wave plate.The second one is amplitude modulation.It can be used to achieve vivid,vibrant,full-color and ultra-high-resolution nano-printings.The third one is near-field enhancement.It can be used to enhance light-matter interaction which can achieve highly sensitive detection and enhancement of nonlinearity.In recent years,the application of metasurfaces has been widely studied.However,there are still two drawbacks.Firstly,although metasurfaces have achieved significant development in term of phase manipulation,amplitude modulation and near-field enhancement,there is a relative lack of comprehensive research on two or three aspects.Secondly,the research on metasurfaces is mainly concentrated in manipulating light with the high refractive index and low loss materials.It does not make profound use of the properties of the materials itself.Especially,many new materials with excellent properties have appeared,such as perovskite with extremely high quantum efficiency and two-dimensional materials with unique properties.It is urgent to develop corresponding metasurfaces to give play to characteristics of those materials.Aiming at solving the above problems,this dissertation pays attention to a further combination of the light field control ability of metasurface and the optical properties of its materials.It includes two aspects.One is to combine the photoluminescence of perovskites with the amplitude modulation of metasurfaces.Another is to combine the phase manipulation and amplitude modulation with the near-field enhancement of metasurfaces.The main innovation and significance of the dissertation are summarized as follows:The whispering-gallery-mode(WGM)modes microlasers have been achieved from synthesized hybrid lead halide perovskite(CH3NH3Pb Br3)microplates and micro rods at room temperature.Their threshold is 138 m J/cm2 and 197 m J/cm2,respectively.Moreover,the three-photon-absorption coefficient was measured in the home-built setup.The value is about 2.26 × 10-5cm3/GW2.This work expands the application of hybrid lead halide perovskites in nonlinear photonic devices.An in-situ dynamic nano-printings was experimentally demonstrated by combining the structural color of metasurfaces and photoluminescence of perovskites.The presented color can be tuned over a broad color gamut by modifying the ratio of the two colors.This approach has a series of advantages in the color generation,especially in in-situ control and non-vacuum environment.This design will pave a new way for the development of nano-printing color display.A double-resonances enhanced nonlinear all-dielectric holography was experimentally demonstrated by combining the nonlinearity of silicon and the light field control ability of silicon metasurface.The near-field enhancement of incident light can significantly enhance the THG process of silicon.Meanwhile,the amplitude modulation of THG signals can suppress the absorption loss of the materials.And the phase manipulation of incident light can control the phase of THG signals.The combination of the two formers can realize the double-resonance enhancement of THG process with a 230-enhancement factor and 1.1×10-6 efficiency.Moreover,the combination of the above three can realize the doubleresonance enhanced nonlinear holography at 483 nm and 417 nm.The design thoughts in this research can be an alternative approach to developing and optimizing the nonlinear metasurfaces for UV and deep-UV regions.