Graphene-based tunable long-pass filter

Abstract

The invention provides a long-wave-pass light filter which is based on graphene and is adjustable in the wavelength range. By means of the long-wave-pass light filter, graphene thin film covers the surface of an optical window, ionic liquid or ionic gel covers the surface of graphene, and electrodes are drawn forth from graphene and the optical window to be connected to a voltage source. By adjusting voltage, the Fermi level of graphene can be changed, then the transmissivity of light within a specific wavelength range is adjusted, that is, the position of the cutoff wavelength of the light filter is adjusted, light of which the wavelength is larger than the cutoff wavelength of the light filter is made emergent from the other side through the light filter, light of which the wavelength issmaller than the cutoff wavelength does not pass through the light filter, and finally, the adjustable long-wave-pass light filter is obtained. Compared with a traditional light filter, the providedlong-wave-pass light filter has the advantages of being adjustable in cutoff wavelength range, low in power dissipation and the like, the traditional light filter can be conveniently replaced, and thelong-wave-pass light filter can be widely applied to the fields like optical engineering and optical instruments.

Description

technical field [0001] The invention relates to an optical device, in particular to a long-wave pass type optical filter. Background technique [0002] An optical filter (or filter) is an optical component that allows specific wavelengths of light to pass through, and other wavelengths of light to reflect, attenuate or absorb. Optical filters are essential basic optical components in optical engineering and optical instruments. In terms of structure and principle, general optical filters are divided into colored glass filters (including dyed plastic and film filters) and dielectric film filters; colored glass filters are absorption filters, and the medium Membrane filters are interference filters. In terms of function, optical filters can be divided into notch type, band pass type, short wave pass type and long wave pass type. When light passes through a colored glass (dyed plastic or film) filter, light of the same color is absorbed by the glass and light of other colors...

AI Technical Summary

Problems solved by technology

At present, all kinds of optical filters are made of plexiglass dyed or coated with a dielectric film on the optical substrate. After the product is formed, the wavelength range of the filter cannot be adjusted, and can only be combined by using filters with different filter ranges. use to achieve the purpose of use

At the same time, the plexiglass dyeing and dielectric layer coating process is a very delicate, expensive and expensive technology

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