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Improving the 3D resolution is a decisive step in the transition of direct laser writing from being limited to research use to being a powerful tool. Three‐color (3CL) lithography is expected to result in significantly higher resolution with two‐color lasers initiating polymerization in two steps and one‐color laser inhibiting polymerization. However, the 3CL process increases the complexity of the system and makes the influence of chromatic aberration worse which leads to non‐ideal writing results, which is ≈80 nm linewidth (≈λ/10) at present. In this study, the 3CL lithography is improved by introducing almost one color (1CL) instead of three colors to achieve subdiffraction 3D nanolithography based on two‐photon two‐step absorption and photoinhibition (T2A‐PI). Using benzil as a photoinitiator, a sub‐30 nm (<λ/17.5) lateral feature size, minimum 80 nm lateral, and 160 nm axial pitches are achieved, which, to our knowledge, is the best to be fabricated using the laser in the visible region. 3D woodpile photonic crystals and other high‐quality nanostructures are fabricated, demonstrating the unique advantages over existing direct laser writing technologies. [ABSTRACT FROM AUTHOR]

Advances in direct laser writing to attain super-resolution are required to improve fabrication performance and develop potential applications for nanophotonics. In this study, a novel technique using single-color peripheral photoinhibition lithography was developed to improve the resolution of direct laser writing while preventing the chromatic aberration characteristics of conventional multicolor photoinhibition lithography, thus offering a robust tool for fabricating 2D and 3D nanophotonic structures. A minimal feature size of 36 nm and a resolution of 140 nm were achieved with a writing speed that was at least 10 times faster than existing photoinhibition lithography. Super-resolution and fast scanning enable the fabrication of spin-decoupled metasurfaces in the visible range within a printing duration of a few minutes. Finally, a subwavelength photonic crystal with a near-ultraviolet structural color was fabricated to demonstrate the potential of 3D printing. This technique is a flexible and reliable tool for fabricating ultracompact optical devices. [ABSTRACT FROM AUTHOR]