Computer-generated hologram using binary phase with an aperture.

Area of Science:

• Optics and Photonics
• Information Security
• Computational Imaging

Background:

• Computer-generated holograms (CGHs) are increasingly utilized in 3D displays, optical security, and beam shaping.
• Existing optical verification methods often require complex setups or are susceptible to manipulation.
• There is a need for robust and efficient optical information verification strategies.

Purpose of the Study:

• To present a novel strategy for optical information verification utilizing computer-generated holograms (CGHs).
• To explore the use of binary phase (1-bit) encoding and aperture selection within CGH for verification.
• To demonstrate the effectiveness of the proposed method for secure optical data authentication.

Main Methods:

• Encoding input information into cascaded phase-only masks (POMs) using iterative phase retrieval.
• Binarizing a selected phase mask and embedding it into a random binary-phase host mask.
• Utilizing a specific aperture to extract and verify the embedded information within the CGH.

Main Results:

• Numerical simulations confirm effective verification of the reconstructed image when system parameters (aperture, POMs) are correctly applied.
• The proposed method demonstrates high sensitivity to parameter variations, indicating robust security.
• Successful reconstruction and verification of the encoded information were achieved.

Conclusions:

• The developed strategy offers a promising approach for CGH-based optical information verification.
• The use of binary phase encoding and aperture selection enhances the security and reliability of optical verification.
• This method has potential applications in secure document authentication and anti-counterfeiting technologies.