Multiplexed volume holographic grating

Abstract

The invention discloses a multiplexed volume holographic grating. The multiplexed volume holographic grating respectively records red, green and blue three holograms on the same dielectric layer by exposing for three times; volume holographic gratings formed by exposure of different wavelengths are the same in inclination angle and are different in period; by controlling exposure time, refractive index modulation depths corresponding to red, green and blue light after exposure accords with the relation that delta n red light is greater than delta n green light, and delta n green light is greater than delta n blue light, and peak diffraction efficiencies corresponding to the red, green and blue light after exposure are similar. The multiplexed volume holographic grating can effectively balance irradiating energy of red, green and blue light waves and avoid color offset.

Description

technical field [0001] The invention belongs to the technical field of holographic grating waveguide display, in particular to a multiplexed volume holographic grating without color shift. Background technique [0002] Holographic waveguide display technology is a display technology that uses a high-brightness microdisplay as an image source, uses transparent holographic goggles as a display screen, and projects images to the human eye through a miniaturized optical system through a waveguide structure. It has the advantages of super large field of view and light weight, and is mostly used in the field of military display. [0003] The working principle of the common monochromatic holographic waveguide display is that the in-coupling grating structure located at the image input end filters the input light wave, the green light is coupled into the waveguide structure, and then transmitted through the waveguide and modulated by the out-coupling grating to carry the virtual ima...

AI Technical Summary

Problems solved by technology

On the one hand, because the depths of the three color light waves entering the grating layer are different, the positions of the diffracted waves entering the waveguide are different, so they cannot reach the outcoupling grating at the same time; Selective, light waves of other wavelengths can be completely transmitted, but in fact, light waves of other wavelengths will introduce a certain degree of loss when passing through, resulting in a large difference in the energy of the three primary colors

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