Optical characteristics investigation on H-PDLC flexible curved radius grating

As an important diffractive optical element, the holographic grating has always been favored by users for its high diffraction efficiency and low cost. Especially in recent years, its value in the near-eye display waveguide structure has been further improved and explored. This paper derives a set of interference field theoretical models suitable for flexible curved radius grating, through the modification of the traditional two-wave interference principle. Based on this, the morphological law of the required interference pattern can be simulated. On the other hand, when we change the radius of flexible grating, the focus position of the diffraction field can be changed correspondingly, so as to achieve the purpose of quantitative focusing. Experiments show that the different degrees of bending of flexible curved radius grating can effectively adjust the focal length of the holographic element, and its diffraction efficiency can always be maintained above 88%. What's more, the imaged brightness uniformity consistent, no interference of diffraction ghost lines, pave the way for the subsequent research on the key technologies of different surface-shaped curved waveguides.