Study On Principle And Methods Of Imaging With Micro-Nano Structures

Micro-nano structures, which are made artificially and have micro and nano characteristic dimension, have shown a lot of novel functions. As the development of optical imaging field toward to lightweight, integrated and large aperture, the traditional imaging technology was confronted with many bottleneck, meanwhile micro-nano structure devices present significant advantage such as planar, high design freedom, flexible, and so on. In this thesis, the imaging principle, design, fabrication and experiment of planar diffractive lens and metasurfaces were systematically researched. This dissertation includes the following parts:1) Base on the Scalar diffraction theory, the principle and methods of imaging with the lightweight planar diffractive lens were proposed. In order to solve the serious dispersion, the achromatic model base on the Schupmann optical structure is analyzed. Then the 5 meter aperture telescope with planar diffractive lens is designed, by adopting the off-axis reflective system to avoid large vignetting. A broadband system design covering visible and part of infrared was presented.2) Two wide bandwidth phase and polarization manipulating principle were represented. Using the metasurfaces, super-octave bandwidth in achromatic phase and polarization conversion was obtained. Utilizing the spin-orbit interaction in ultrathin space-variant and spectrally engineered metasurfaces, the electromagnetic character of object was changed without modifying the geometrical shape. Base on the principles above, two novel imaging devices respectively using transmittive and reflective metasurfaces were designed. These devices can generate optical vortex or image in infrared range.3) The 3-dimension optical field testing stage for imaging middle field measurement was developed. The irregular 20 nm nano structures of metasurfaces and 32 levels deep sag micro-nano structures were fabricated. The broadband achromatic imaging result of planar diffractive lens is represented, in order to proving the validity of achromatic theory.In conclusion, the dissertation discusses the principle and methods of imaging with micro-nano structures. Several results are obtained, including achromatic imaging theory, broadband phase and polarization manipulating principle, planar diffractive lens and metasurfaces design methods, fabrication of precise micro-nano structures, experiments at microwave and visible range. Obviously, these researches will be helpful for the further explorations of micro-nano structures.