Holographic optical elements with a large adjustable focal length and an aberration correction.

Abstract

Holographic optical element (HOE) has the advantages of light weight, small volume and multiple functions, but the fixed focal length limits its application. The current methods of adjusting focal length suffer from the disadvantages of small adjustable range and the introduction of aberration. This paper proposes a design method for HOE, and it can compensate the aberrations of the reconstructed image for each distance in a large adjustable range. The focal length of HOE is adjusted by modulating the incident light through the wavefront modulator, and the aberration of the reconstructed image is corrected by optimizing the phase distribution of HOE and superimposing different compensation phases for different reconstruction distances. The reconstructed image experimentally moves without aberration in a large range, which demonstrates the feasibility of the proposed method. It is expected to be widely used in various optical fields where the focal length of HOE needs to be dynamically tuned.