A polarization-sensitive long-wave infrared subwavelength grating mdm trapezoidal absorber

Abstract

The invention discloses a polarized light-sensitive long-wave infrared subwavelength grating MDM trapezoidal structure absorber, comprising a zinc sulfide substrate, the bottom of the substrate is plated with an aluminum film, and the upper part of the substrate is plated with aluminum film, selenization from bottom to top. The trapezoidal grating structure layer of zinc film, aluminum film, germanium film and aluminum film; the invention adopts the processing technology of photolithography, etching and coating, and can realize absorption only by changing the duty ratio or period of the micro-nano structure The translation regulation of the peak center wavelength, and the realization of ultra-wide-angle narrow-band high absorption under multi-azimuth angles, in the comprehensive array area, for the same film layer of multiple groups of striped micro-nano structures, to achieve simultaneous processing and preparation. It overcomes the problems of the order of magnitude increase in the number of coatings caused by multiple coatings in time-division and regional areas in the traditional coating process, and the difficulty of ensuring the relative parallelism of the multi-strip dissimilar coatings, improving the processing efficiency and reducing the polarization spectrum in the full array area. The difficulty and complexity of the fabrication of spectroscopic devices is of innovative significance.

Description

technical field [0001] The invention belongs to the technical field of micro-nano optical devices, in particular to a polarized light-sensitive long-wave infrared subwavelength 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 always attracted the attention of scholars at home and abroad, and therefore has become an important method. Research hotspots. Since 1976, Maystre et al. have published about their discovery of total absorption in diffraction gratings, and in 1998 Ebbesen et al. discovered that periodic pinhole metal films exhibited anomalous transmission at specific wavelengths, which made subwavelength metal films The grating structure has been ...

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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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