Lawrence Livermore National Laboratory (LLNL) engineers and Stanford University researchers have developed a new approach to two-photon lithography (TPL) that significantly increases manufacturing speed while maintaining nanoscale precision. The team’s method, published in Nature, uses metalens arrays to split a femtosecond laser into more than 120,000 coordinated focal spots that operate simultaneously across centimeter-scale areas. The system achieves throughput more than a thousand times faster than commercial systems while producing 3D structures with minimum feature sizes of 113 nanometers.
3D Nanofabrication method using metalens arrays (Credit: LLNL)
Traditional TPL has been limited by its reliance on microscope objectives, which confined printable areas to a few hundred microns. Larger prints required stitching thousands of tiles together, creating alignment errors and preventing industrial adoption. The new metalens TPL approach replaces the microscope objective with a tiled array of high-numerical-aperture metalenses, with each lens functioning as a miniature printer.
The team integrated a spatial light modulator that adjusts the intensity of each focal spot in real time, allowing the system to switch beams on or off and control linewidths. “During the project, we realized that by dynamically switching the focal spots on and off and carefully planning the printing trajectory, we can actually print fully stochastic structures with a high degree of parallelization,” said Xiaoxing Xia, an LLNL materials engineer and principal investigator. This adaptive capability enables the fabrication of non-periodic structures and complex designs.
The technology, named MetaLitho3D, has potential applications in microfluidics, quantum information, microelectronics, photonics, and biomedicine. The platform can fabricate tens of millions of micro-particles per day and could scale up LLNL’s research on 3D printing fusion fuel capsules and quantum computing chips. The technology recently won a 2025 R&D 100 Award, suggesting commercial viability for industrial applications.
Source: llnl.gov