Subdiffraction-Limit Glass 3D Printing by Optical Force-Guided Polymerization With Two Continuous Wave Lasers

The realization of free-form silica glass nanostructures with sub-200 nm resolution represents a critical capability for advanced photonics and precision optics. Current femtosecond laser-based approaches remain constrained by high costs, low throughput, and restricted fabrication areas. A novel nanoscale additive manufacturing technique employing continuous-wave laser excitation is presented in a thermally curable polyhedral oligomeric silsesquioxane (POSS) photoresin, subsequently convertible to fused silica at 650 °C. The system utilizes synchronized coaxial laser beams to implement two distinct photochemical mechanisms: a two-color two-step absorption process for spatial confinement and optical force-guided polymerization (OFGP) for subdiffraction pattern refinement. This synergistic approach overcomes spatial resolution limitations imposed by the photopolymer's memory effect, achieving an exceptional feature size of 102 nm, surpassing the optical diffraction limit. Experimental validation demonstrates successful fabrication of high-fidelity curved surface architectures and programmable grayscale lithography with extended voxel modulation range. This dual-laser nanofabrication platform establishes a new paradigm for glass-based micro-optics production, combining nanoscale precision with industrial-scale throughput capabilities.