Polarized light sensitive long-wave infrared sub-wavelength grating MDM trapezoidal structure absorber

Abstract

The invention discloses a polarized light sensitive long-wave infrared sub-wavelength grating MDM trapezoidal structure absorber. The structure absorber comprises a zinc sulfide substrate, wherein the bottom of the substrate is plated with an aluminum film, and an upper portion of the substrate is plated with a trapezoidal grating structure layer sequentially comprising an aluminum film, a zinc selenide film, an aluminum film, a germanium film and an aluminum film from bottom to top. According to the structure absorber, a processing technology combining photoetching, etching and film coating is adopted, translation regulation and control of the central wavelength of an absorption peak can be realized only by changing the duty ratio or period of the micro-nano structure, ultra-wide-angle narrow-band high absorption is realized under multiple azimuth angles, and simultaneous processing and preparation are realized for the same film layer of multiple groups of strip micro-nano structures in a full array area; problems that in a traditional coating process, due to the fact that coating is conducted for multiple times in a time-division and area-division mode, the order of magnitude of the number of times of coating is increased, and the relative parallelism of dissimilatory coating of multiple strips is difficult to guarantee are solved, machining efficiency is improved, machining and preparing difficulty and complexity of the polarization spectrum light splitting device in the full-array area are reduced, and innovative significance is achieved.

Description

technical field [0001] The invention belongs to the technical field of micro-nano optical devices, and in particular relates to a polarized light-sensitive long-wave infrared sub-wavelength grating MDM trapezoidal structure absorber. Background technique [0002] Perfect light absorption is an efficient way to convert light energy into other forms of energy. Absorbers are widely used in a variety of disciplines. As an important means to improve their optical properties, especially the application of perfect absorption properties to the field of detectors has attracted the attention of scholars at home and abroad, and has therefore become an important Research hotspots. Since 1976, Maystre et al. have published about the total absorption phenomenon they found in diffraction gratings, and with the discovery in 1998 of Ebbesen et al. Grating structures have been advanced. In 2008, Landy et al carried out research on perfect absorbers based on artificial electromagnetic mater...

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Problems solved by technology

[0003] At present, there are more researches on broadband absorption in the long-wave infrared band and less research on narrow-band absorption. At present, there are problems in the existing technology that can not achieve overall narrow-band absorption in the long-wave infrared 7-14um range, and under the conditions of wide incident angle and azimuth ultra-wide angle To achieve narrow-band high absorption, we used finite element analysis method to propose a polarization-sensitive sub-wavelength grating MDM structure based on the principle of surface plasmon resonance on the grating structure, which solved the problem of having tunable in the long infrared band Wide-angle and narrow-band high-absorption, while only changing the parameter values ​​​​of the duty cycle or period, and the parameter values ​​​​of the rest of the structural film layer are unchanged, the central wavelength of the absorption peak can be adjusted in the long-wave infrared band. As the space ratio or period increases, the spectral absorption curve shows a red shift phenomenon, and at the same time, it can achieve wide-angle, narrow-band high absorption under the condition of multi-azimuth angle (0°-90°)

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