Method for expanding field angle bandwidth of holographic waveguide display system

Abstract

The invention discloses a field angle expanding method for a holographic waveguide display system. The method comprises the following steps that: step 1, the diffraction angle bandwidth of single volume holographic gratings is expanded based on a reflection type volume holographic grating Kogelnik coupling wave theoretical model; 2, multiple gratings are recorded in one photosensitive film througha multi-angle multiplexing technology, and the expansion of the diffraction angle bandwidth is achieved; and 3, the parameters of the grating are optimized on the basis of the spectrum curve of a wide-spectrum light source, so that the diffraction angle bandwidth of the gratings can be expanded. With the method comprising the above step 1 to 3 adopted, the field angle of the holographic waveguidedisplay system can be improved, and the problem that the field angle of a traditional holographic waveguide display device is small is solved.

Description

technical field [0001] The invention relates to a method for expanding the viewing angle bandwidth of a holographic waveguide display system, and belongs to the technical field of augmented reality near-eye display. Background technique [0002] In recent years, many researchers have been studying a holographic waveguide structure. The input and output optical coupling elements of this structure are reflective volume holographic gratings with mirror symmetry. . The display principle of this structure is that the image emitted by the microdisplay is firstly collimated by the collimating optical system, then diffracted into the holographic waveguide through the in-coupling holographic grating, and finally coupled into the human eye through the output holographic grating. After research, the field of view of the holographic waveguide display configuration is mainly determined by the collimation optical system and the angular wavelength bandwidth of the volume holographic grati...

AI Technical Summary

Problems solved by technology

However, this solution requires a high degree of modulation of the refractive index of the holographic recording material used to prepare the grating, and the grating exposure process is complicated

[0003] In the above several schemes, the input and output optical coupling elements are reflective volume holographic gratings, and the field of view expansion effect is not ideal, and the design and process are relatively complicated. Therefore, a new scheme is urgently needed to solve the above technical problems

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