Grating polarizer

Abstract

The invention relates to a grating polarizing plate, which includes a base and a plurality of grating line units. A plurality of gate line units are periodically disposed on one surface of the substrate, and each gate line unit includes a grating dielectric layer, a first metal layer and a second metal layer respectively. The grating dielectric layer is disposed on the substrate, and the grating dielectric layer includes a bottom surface close to the substrate, a top surface away from the substrate, and two side surfaces connecting the bottom surface and the top surface. The width of the top surface of the grating dielectric layer is smaller than the width of the bottom surface, the first metal layer is disposed on the top surface of the grating dielectric layer, and the second metal layer is located between the adjacent grating dielectric layers. The height of the top surface of the grating dielectric layer is greater than the height of the second metal layer. In the grating polarizer structure of the present invention, it is simple to prepare, has high TM light transmittance and a high extinction ratio. At the same time, in the visible light band, the TM light transmittance remains basically stable in different wavelength ranges.

Description

technical field [0001] The invention relates to the technical field of polarizers, in particular to a grating polarizer. Background technique [0002] Polarizer is a very important optical component in liquid crystal display, optical measurement, optical communication and other systems, and it has a very broad market. [0003] Polarizers can generally be divided into reflective and refractive polarizers, dichroic polarizers, birefringent crystal polarizers and other traditional polarizers and grating polarizers. Traditional polarizers are too bulky, have a complicated manufacturing process, and only have a large extinction ratio in a small wavelength range, which cannot meet the requirements of the display industry for light weight, ultra-thin, and low cost. [0004] Among the existing grating polarizers, the metal grating polarizer has unique polarization performance, which is due to the different boundary conditions of the polarized light perpendicular to the grating vect...

AI Technical Summary

Problems solved by technology

In the existing double-layer metal grating polarizer, it is required that the two metal layers 4, 5 and the grating dielectric layer 6 below the metal layer 4 are all rectangular structures, and at the same time, because the period P between the metal gratings is required to be less than 200nm, in When the metal layer 5 is vapor-deposited, the two side walls of the metal layer 5 are steep structures, so its preparation is difficult, and it will also reduce the transmission efficiency and extinction ratio of TM light. The extinction ratio refers to the transmission efficiency and extinction ratio of TM light. The ratio of the transmission efficiency of TE light

And in the existing double-layer metal grating polarizer structure, in the visible light band, the transmittance of TM light has large fluctuations in different wavelength ranges, so the visible light transmittance of different wavelengths varies greatly

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