Femtosecond Laser Two-Photon Polymerization for 3D Micro-Nano Machining

The patent segments the light-sensitive material into multiple thin layers (e.g., 10-50 μm thickness) and processes each layer independently through sequential imaging and development. This segmentation allows parallel processing of multiple structures within each layer while maintaining precise spatial control through the threshold effect of two-photon absorption, thereby resolving the contradiction between precision and productivity.

The patent performs preliminary actions by first creating a master template with the desired three-dimensional micro-nano structure pattern, then using this template to generate multiple copies through contactless imaging and transfer to new layers. This preliminary template creation enables subsequent rapid replication of complex structures without repeatedly machining each feature point-by-point, significantly improving productivity while preserving spatial precision.

The patent uses contactless imaging techniques (such as projection lithography or direct laser writing) to create optical copies of the desired micro-nano structure pattern and transfer them directly to the light-sensitive material layers. This copying approach allows any complex three-dimensional structure to be replicated without requiring mechanical motion or pre-programmed multifocal patterns, providing both high productivity through parallel processing and unlimited adaptability for arbitrary structure designs.

The patent replaces the mechanical scanning system with optical field-based patterning methods. Instead of moving the focal point mechanically point-by-point or using complex multifocal mechanical arrangements, the invention uses optical projection and contactless imaging to define the entire structure pattern in each layer simultaneously. This substitution of mechanical systems with optical fields enables both high-speed parallel processing and complete freedom in structure design complexity.