Optoelectronic information encryption with phase-shifting interferometry

TLDR

The authors introduce a high‑speed, high‑security optical encryption technique that integrates electronic transmission, storage, and decryption, and can encrypt either Fraunhofer or Fresnel diffraction patterns. Digital phase‑shifting interferometry records phase and amplitude with an intensity detector, using two random phase codes in the object and Fresnel planes for encryption, and electronic decryption is achieved via a single‑step fast Fourier transform reconstruction. Experimental results demonstrate the feasibility of both lensless and conventional setups.

Abstract

A technique that combines the high speed and the high security of optical encryption with the advantages of electronic transmission, storage, and decryption is introduced. Digital phase-shifting interferometry is used for efficient recording of phase and amplitude information with an intensity recording device. The encryption is performed by use of two random phase codes, one in the object plane and another in the Fresnel domain, providing high security in the encrypted image and a key with many degrees of freedom. We describe how our technique can be adapted to encrypt either the Fraunhofer or the Fresnel diffraction pattern of the input. Electronic decryption can be performed with a one-step fast Fourier transform reconstruction procedure. Experimental results for both systems including a lensless setup are shown.