A method and component for realizing near-field display and far-field holography based on nano-microcavity

Abstract

The present invention relates to a method and component for realizing near-field display and far-field holography based on a nano-microcavity. The nano-microcavity refers to a three-layer film structure composed of a metal layer-dielectric layer-metal layer. The method includes: Based on the corresponding relationship between the transmittance of the spectrum and the thickness of the dielectric layer of the nano-micro-cavity, a nano-micro-cavity array containing multiple nano-micro-cavities is formed, so that each nano-micro-cavity has a high transmittance to a spectrum of a selected central wavelength or is in the opposite direction. Selecting a spectrum with a central wavelength for high transmission and a spectrum with a selected central wavelength for low transmission is optional, and wherein part of the dielectric layer of the nano-microcavity has at least two optional thicknesses to provide two different reflections Phase; determine the near-field display by the transmission of the spectrum of different central wavelengths in the nano-microcavity array; use an optimization algorithm to calculate the phase distribution of the nano-micro-cavity array and calculate the far-field hologram according to the phase distribution.

Description

technical field [0001] The invention relates to micro-nano optics and optical thin film technology, in particular to a method and element for realizing near-field display and far-field holography based on nano-microcavity. Background technique [0002] At present, the three-layer film structure composed of sub-wavelength metal layer-dielectric layer-metal layer can form F-P interference effect, and the nano-microcavity formed under the condition of selecting appropriate materials and thickness can show good wavelength selection. This wavelength selectivity is manifested in that when the thickness of the upper and lower metal layers is fixed, by changing the thickness of the dielectric layer, the narrow-band transmission at different central wavelengths in the visible light band can be achieved, and then the transmitted light with high saturation and different colors can be obtained. The underlying metal is set to be thicker, so as to achieve full absorption of the transmitte...

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Problems solved by technology

[0004] However, the microstructure of metasurface processing is relatively complex, requires high precision, and the corresponding manufacturing cost is also high.

At the same time, since the near-field spectrum is highly consistent with the spectral range that can achieve far-field holography, it leads to the problem that the near-field spectrum constrains the holographic bandwidth.

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