Single-exposure holographic 3D printing via inverse-designed phase masks

Abstract

Additive manufacturing using light is commonly constrained by serial voxel-by-voxel or layer-by-layer processing, which fundamentally limits fabrication speed and scalability. Here, we introduce a single-exposure holographic three-dimensional (3D) printing approach that synthesizes an entire volumetric dose distribution optically in one step. The method combines inverse-designed microstructured phase masks with photopolymer resins engineered for controlled optical absorption. By precisely tailoring the phase-mask topography, we generate arbitrary 3D light-intensity distributions within the resin, including intentionally encoded dark regions that define hollow internal features. Simultaneously, the resin formulation is designed to balance optical penetration with sufficient local energy deposition to achieve high-fidelity polymerization throughout the volume. Using this approach, millimeter-scale architectures comprising more than $10^{6}$ addressable voxels are fabricated in a single 7.5~s exposure, corresponding to a volumetric throughput of $\sim$1~mm$^{3}$/s ($>10^{5}$~voxels/s). The demonstrated performance is presently limited by resin kinetics and illumination geometry rather than by the phase-mask framework itself. Because the volumetric information capacity scales with the space--bandwidth product of the phase mask, this approach provides a clear pathway toward substantially higher throughput, enabling scalable fabrication of micro-optical components, biomedical scaffolds, and other precision-engineered mesoscale systems.

Figures (3)

• Figure 1: Single-exposure holographic additive manufacturing. (A) State-of-the-art volumetric fabrication rely on multiple exposures via scanning light-sheets, via tomographic (angle-resolved) projections into a rotating vat containing resin, or via orthogonal multi-angle beam projections. (B) In contrast, our approach generates arbitrary 3D holographic intensity distributions using a static phase mask. The mask encodes volumetric information via a spatial sampling grid for high axial resolution. In our demonstration, the mask, fabricated via grayscale lithography, measures $2.4 \times 2.4 \text{mm}^2$ with $1.5\mu$m minimum features. Right panel shows a small portion of the simulated 3D holographic light distribution of the hollow cylinder illustrating high axial resolution (see details in Fig. \ref{['fig:inverse_design']}). (C) The computed 3D intensity distribution is projected into a UV-curable resin, enabling simultaneous volumetric polymerization in a single exposure. (D) Mask and resin parameters are co-optimized to ensure localized light distributions (Gaussian “dots”) merge into a continuous 3D structure upon exposure.
• Figure 2: Inverse design of the phase mask for single-shot 3D fabrication. (A) Workflow for generating 3D target intensity distributions from computer-aided design (CAD) models. The continuous volumetric geometry is first discretized into axial slices along the light propagation direction. Each slice is then sampled using Gaussian focal spots, and a depth-dependent intensity gradient is applied to compensate for optical attenuation within the photoresin. (B) Inverse-design framework for phase-mask optimization. A depth-averaged loss function is minimized by iteratively updating the phase mask using back-propagated loss gradients, in direct analogy to gradient-based optimization in deep learning. (C) Measured 3D holographic intensity distribution, showing solid pillars and a hollow cylindrical core. (D) Magnified intensity maps from pillar and non-pillar regions, resolving individual sampled dots and confirming the absence of light in the hollow wall. (E) Optical micrograph of a representative region of an exemplary phase mask.
• Figure 3: Single-exposure holographic 3D printing. A, Schematic of the experimental setup, where a shutter controls exposure duration. B–E, Optical and scanning electron micrographs of representative structures, a hollow cylinder and a cube, fabricated in a single exposure. Prints in B, C, and E used 15 s exposures, while D was produced in 7.5 s. The multiple windows visible in C and E arise when the resin thickness exceeds the designed volume. F, Time-lapse images of the hollow cylinder, recorded at 1 s intervals, reveal real-time progression of polymerization. Illumination was provided at 850 nm, with a long-pass filter before the camera to enhance contrast.