Wire grating wideband polarizer and method of producing the same

Abstract

The present invention provides a metal wire grating polarizer and a preparation method thereof, which belongs to optical devices. The object is that the present invention is of high polarized light extinction ratio, high luminous flux, simple structure and the wide range of working wavelength. The polarizer of the present invention deposits a metal aluminum nanometer wire gating on a substrate. The substrate is optical materials which are transparent from ultraviolet band to infrared band. The structure parameter of the metal aluminum nanometer wire gating is as follows: the wire gating cycle length ranges from 40 to 80 nanometers; the wire gating duty cycle is 40 percent to 60 percent; the interlayer distance is 10 to 20 nanometers. The method steps of the present invention are as follows: the substrate is cleaned; a protection film is deposited on the surface of the substrate; a photoresist is spin coated; the nanometer wire gating structure is formed on the surface of the photoresist; the nanometer wire gating structure is carved on the protection film; nanometer wire gating structure is carved on the substrate; the rest protection film is eliminated; an aluminum metal film is coated on the vertical surface of the substrate; a parallel strip nanometer wire gating is formed. The polarization extinction ratio of the wideband polarizer of the present invention can reach 33 to 37dB in the wave band range of 300 to 5000 nanometers, and the polarized light transmittance can reach 68 percent to 94 percent.

Description

technical field [0001] The invention belongs to an optical device in an optical system, in particular to a metal wire grid polarizer and a preparation method thereof. Background technique [0002] Polarizers can generally be classified into: dichroic polarizers, anisotropic crystal polarizers, Brinell polarizers and wire grid polarizers. But each of the above polarizers can only correspond to a small and relatively fixed operating wavelength range. For many optical and optoelectronic applications, it is desirable to obtain a broadband polarizer that can operate over the entire UV-Vis-IR wavelength range. [0003] A nanometal wire grid polarizer is one such device that can meet this requirement. So far, subwavelength metal wire grid polarizers have been widely used in the radio wave, microwave and far infrared fields. Moreover, with the continuous development of nano-processing technology, it has become possible to prepare such polarizers with smaller lines and apply them ...

AI Technical Summary

Problems solved by technology

These latest research results have proved that the use of metal wire grid polarizers can realize devices working in the near-infrared, visible, and ultraviolet bands, but researchers have never solved the problem of using a polarizer to work in the infrared, visible, and ultraviolet bands at the same time. a problem

In 2007, a research team of Huazhong University of Science and Technology in Wuhan, China proposed a polarizer with a metal-coated aluminum nanowire grid structure on a calcium fluoride substrate, and its working wavelength can reach 300-5000 nanometers, see the literature Z.Y.Yang and Y.F.Lu, " Broadband nanowire-grid polarizers in ultraviolet-visible-near-infrared regions, "Opt.Express, vol.15, no.15, Jul.2007, pp.9510-9519, but the structure of this polarizer is very complicated, it needs to be in Metal nanowire grids are prepared on both the upper and lower surfaces of the substrate, which greatly increases the difficulty of the manufacturing process

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