Narrow-period long-wave infrared multi-layer grating structure

Abstract

The invention discloses a narrow-period long-wave infrared multi-layer grating structure and a preparation flow thereof, thereby solving a problem that the infinite grating area precondition can not be met when the existing large-period gratings form a grating array. The narrow-period long-wave infrared multi-layer grating structure comprises a grating layer, a base layer and a high-reflection layer that are arranged in order from top to bottom. The high-reflection layer includes three layers including a high-reflection layer high-refractive-index layer and high-reflection low-refractive-index layers that are arranged on the upper and lower surfaces of the high-reflection layer high-refractive-index layer. The grating layer and the base layer have the same thicknesses; and the two high-reflection low-refractive-index layers have the same thicknesses. The grating layer contains a high refractive index material and a low refractive index material that are distributed on the same plane; and the high refractive index material is tantalum and the low refractive index material is germanium. The base layer is made of germanium being a metal material; the high-reflection layer high-refractive-index layer is made of a germanium material; and the high-reflection low-refractive-index layers are made of sodium chloride materials.

Description

technical field [0001] The invention belongs to the technical field of micro-nano device design, and relates to a narrow-period long-wave infrared multilayer bandpass grating structure whose grating period can be adjusted freely within 0.1 μm-1 μm. Background technique [0002] A grating is a basic unit of a multispectral filter array. The multispectral filter array composed of gratings is compact, small in size, light in weight, and does not require additional driving equipment. It is an important research direction in the field of multispectral imaging. Designing a grating structure with good bandpass characteristics and low sideband effects is the premise and basis for the design of multispectral filter arrays. [0003] Guided mode resonant subwavelength filter devices have attracted extensive attention in recent years because of their advantages such as extremely narrow bandwidth, high diffraction efficiency and low sideband effects. For sub-wavelength waveguide gratin...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a narrow-period long-wave infrared multi-layer grating structure in view of the above-mentioned deficiencies in the prior art, which solves the problem that the existing large-period grating cannot satisfy the precondition of an infinitely large grating area when forming a grating array The problem

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