Doubled Z-axis scanning range and spot-quality enhancement in system-level integrated co-optimized transmissive 3D laser scanning systems.

Transmissive three-dimensional (3D) laser scanning systems are promising for precision micro- and nanofabrication, but their scanning range is limited by cumulative optical path difference (OPD) induced by large-field angular scanning and dynamic axial focusing. We propose a system-level integrated co-optimization (SLICO) strategy in which the dynamic focusing module, XY galvanometric scanner, and F-theta telecentric lens are jointly modeled and optimized for collaborative aberration compensation as a unified system. Simulations demonstrate that, over an 80 mm diameter XY scanning field and with the Z-axis scanning range extended from ±10 mm to ±20 mm, the OPD is reduced from 1.0 to 0.25 waves and the Strehl ratio (STRH) rises from 0.3 to above 0.96. Experimental validation confirms the strategy's feasibility and performance. This co-optimization strategy significantly enlarges the scanning field for a high-quality focal spot and provides a practical solution for high-precision, large-range laser fabrication.