Unlock instant, AI-driven research and patent intelligence for your innovation.

Generating certifiable phase-only holograms based on phase optimization and sparsity constraints

A Phase-Optimized, Sparse-Constrained Technique

Active Publication Date: 2022-05-27
ZHEJIANG UNIVERSITY OF SCIENCE AND TECHNOLOGY
View PDF19 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In forward and reverse diffraction calculations, often multiple iterations are required to achieve convergence in the optimization process, and thus high-quality reconstruction of holograms is often time-consuming

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Generating certifiable phase-only holograms based on phase optimization and sparsity constraints
  • Generating certifiable phase-only holograms based on phase optimization and sparsity constraints
  • Generating certifiable phase-only holograms based on phase optimization and sparsity constraints

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033]Example 1: A method for generating certifiable phase-only holograms based on phase optimization and sparse constraints, such as figure 1 shown, including the following steps:

[0034] S1: Select three images as hidden image, reference image and host image respectively, such as figure 2 shown, figure 2 The hidden image in is (a), the reference image is (b), and the host image is (c); using the phase optimization method of the first stage ( figure 1 The first stage of optimization) generates phase-only holograms corresponding to the hidden image, the reference image and the host image under the sparse constraints, respectively, such as image 3 shown, image 3 (a) is the pure phase hologram generated by the hidden image; (b) is the pure phase hologram generated by the reference image; (c) is the pure phase hologram generated by the host image (corresponding to figure 1 Hologram1, Hologram2 and Hologram3 in );

[0035] S2: Perform secondary phase optimization on the ...

Embodiment 2

[0036] Embodiment 2: On the basis of Embodiment 1, the specific process of the phase optimization method in the step S1 is as follows:

[0037] (i) Select a phase plate of suitable size and determine the corresponding blank rectangular window |A 0 |=1, multiplied by a random phase in the range [0, 2π] Make up the input light field

[0038] (ii) put the input light field Perform the inverse Fresnel transform to get the function replace the function a with a constant 1 q The magnitude component in yields the function a q ', to simulate the missing amplitude modulation of the pure-phase SLM plane, and then to the function a q 'Fresnel transform to get the function And replace the calculated approximation with the initial amplitude component (constant 1), continue to perform the inverse Fresnel transform after the replacement, and repeat this iterative cycle;

[0039] Among them, the Fresnel transform is expressed by the following formula:

[0040]

[0041] where ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a method for generating a verifiable phase-only hologram based on phase optimization and sparse constraints, which includes the following steps: S1: select three images as hidden images, reference images, and host images, respectively, and use phase optimization to generate holograms under sparse constraints. Generate the phase-only hologram corresponding to the hidden image, the reference image and the host image under certain conditions; S2: Perform phase optimization twice on the phase-only hologram corresponding to the hidden image and the reference image respectively, obtain the optimized phase-only hologram respectively, and then After the hidden image and reference image are optimized, the phase information of the phase-only hologram is embedded in the phase-only hologram of the host image and remains unchanged. The phase-only hologram of the host image is optimized again to obtain the final verifiable phase-only hologram. Hologram. The invention can effectively encrypt the hidden image, and can obtain good authentication effect.

Description

technical field [0001] The invention relates to the technical field of information security, in particular to a method for generating a certifiable pure phase hologram based on phase optimization and sparse constraints. Background technique [0002] In the field of information security, compared with electronic technology, information security systems based on optical methods have multi-degree-of-freedom or multi-dimensional characteristics in protecting information, such as amplitude, phase, wavelength, polarization, etc. In recent years, the realization of information security by optical means has been widely studied. Such as diffraction imaging, digital holography, integral imaging, etc. In contrast, holography is an attractive display technology because it can provide all object information and has a wide range of applications including augmented reality displays, neuronal photostimulation, optical trapping, parallax correction, and other fields. For electron holograp...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): G06F21/60
CPCG06F21/602G06F2221/2107
Inventor 汪小刚王雯琦
Owner ZHEJIANG UNIVERSITY OF SCIENCE AND TECHNOLOGY