Pure phase holographic projection method for inclined plane

Abstract

The invention discloses a pure phase holographic projection method for an inclined plane. The method comprises the following steps: 1) arranging projection equipment: sequentially arranging a phase spatial light modulator, a beam splitter prism, a lens and a screen, arranging a single-color laser and a polarizing sheet on the same side of the beam splitter prism, and connecting the phase spatial light modulator with a computer; 2) determining parameters in a system such as an inclined angle of the inclined plane, the sampling interval and resolution of the spatial light modulator, and the focal distance of the lens; 3) performing iterative calculation by using coordinate rotation, an interpolation algorithm and a fractional order Fourier transformation and inverse transformation formula to obtain the phase of a two-dimensional image; and 4) transmitting a phase hologram to the phase spatial light modulator through the computer, and projecting the phase hologram to an inclined screen at an appointed position by using the phase spatial light modulator. According to the holographic projection method, the two-dimensional image which is reconstructed by the hologram can be projected to the inclined plane at a random position behind the lens, and the distance of the inclined plane can be conveniently controlled.

Description

technical field [0001] The invention relates to a holographic projection method, in particular to a phase-only holographic projection method of an inclined plane. Background technique [0002] For the traditional calculation of the propagation of the light field distribution of the inclined plane in space, the general method is: first calculate the light field distribution of the reference plane through the coordinate rotation of the angular spectrum domain, and then pass the light through the parallel plane in space In this case, the optical field distribution obtained on the holographic surface is in the form of complex amplitude, that is, it contains both amplitude information and phase information, so it is necessary to To achieve pure phase modulation, the complex amplitude must be phase-encoded, which increases complexity and error. On the other hand, for the traditional phase-only holographic projection, the phase hologram is generated using the classic Gerschberg-Sa...

AI Technical Summary

Problems solved by technology

But in this technology, the imaging plane is parallel to the holographic plane, and the phase hologram can only be projected on the plane parallel to the holographic plane in space, and the projected image is always formed on the back focal plane of the lens, and the imaging distance is also It is the focal length of the lens, which has certain limitations for practical applications.

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