Zero-Order Diffraction Suppression in Full Field-of-View Computer Generated Holography: A Camera In the Loop Interferometric Approach

TL;DR

This paper presents a camera-in-the-loop interferometric method for suppressing zero-order diffraction in phase-only holography, enabling high-fidelity, real-time holographic displays suitable for augmented reality applications.

Contribution

It introduces a novel calibration technique that achieves up to 99% ZOD suppression without degrading image quality, allowing real-time holography with stable performance.

Findings

Achieved up to 99% ZOD suppression in experiments.

Enabled real-time hologram correction without recomputation.

Maintained image quality and full field of view.

Abstract

We introduce a novel interferometric approach for suppressing zero-order diffraction (ZOD) in phase-only computer-generated holography. The technique relies on the destructive interference between the zeroth-order light and a suppression beam in a plane optically conjugated to the spatial light modulator (SLM). A camera-in-the-loop (CITL) calibration procedure retrieves the optimal pixel-wise phase map that cancels out the ZOD component with high precision, while preserving the full modulation depth of the SLM. Experimental demonstrations on point-cloud and 2D/3D holograms achieve up to 99% suppression of the ZOD intensity, without loss of image quality or field of view. Once calibrated, the correction can be applied to any hologram without recomputation, enabling real-time operation and robust performance over time. This method removes a long-standing barrier to the practical deployment of full-field holography, facilitating the development of compact, high-fidelity holographic engines for augmented and mixed reality displays.