Single-lens zero-order noise elimination with Fresnel lens compensation.

Computer-generated holography (CGH) based on Fresnel convolution diffraction has been widely explored for three-dimensional displays. However, zero-order noise-manifesting as a high-intensity and heavy-artifact background-remains a major limitation that degrades image contrast and quality. In this work, we propose a single-lens system to eliminate this noise, where a converging lens focuses and a focal-plane mask blocks the noise respectively. To preserve the characteristics of Fresnel convolution diffraction, a lens compensation algorithm is introduced to correct lens-induced distortions. Beyond zero-order noise suppression, the proposed method also improves image sharpness and reconstruction quality. Compared with the conventional 4f system, our approach offers a simpler and more compact optical configuration. At longer propagation distances, it also demonstrates clear advantages over the 4f system by maintaining a substantially wider hologram bandwidth, thereby reducing mask-induced distortions and preserving higher image integrity. Experimental results show a 136% improvement in image integrity at a propagation distance of 850 mm. Furthermore, we incorporate mask modeling into the Gerchberg-Saxton algorithm to alleviate mask-induced degradation and optimize image quality.