Phase-aligned wavefront record plane algorithm for single-exposure holographic two-photon lithography.

Abstract

Holographic two-photon polymerization (2PP) promises high-throughput 3D micro/nano-fabrication; however, generating high-fidelity continuous 3D structures remains challenging due to severe inter-point spatial crosstalk and uneven axial intensity distribution. Here, we propose a phase-aligned wavefront record plane (PAWRP) algorithm coupled with an adaptive feedback loop for single-exposure continuous 3D volumetric lithography. By substituting conventionally used spherical waves with focused Gaussian beams, this approach flattens the wavefront phase and essentially eliminates inter-point interference-induced undesired intensity non-uniformity. With the help of this method, we successfully fabricated double-layer woodpile-like scaffold structures featuring sub-150 nm lateral linewidths and continuous, uniform sub-micron axial heights without any mechanical z-scanning. This mechanical-scanning-free method provides an efficient, high-resolution paradigm for high-throughput 3D holographic nanofabrication.