Femtosecond laser drilling of epoxy composites: a review of mechanisms, modeling, and adaptive control

Abstract This review synthesizes recent progress in femtosecond (fs) laser drilling of epoxy composites, focusing on three interconnected themes critical for industrial scalability: ablation threshold dynamics, multiscale modeling, and adaptive process control. It quantifies how incubation effects reduce multi-pulse ablation thresholds, enabling precise material removal with minimal heat-affected zones. A unified multiscale simulation framework is presented, integrating continuum models, molecular dynamics, and plasma simulations to capture ultrafast energy deposition and stress evolution across vast spatiotemporal scales. To overcome throughput limitations, advanced process control strategies leveraging multimodal diagnostics and machine learning are discussed, demonstrating sub-micron precision and enhanced efficiency. The review concludes by identifying key challenges, such as the need for standardized characterization methods and low-latency feedback systems, and outlines a roadmap for future research, emphasizing the potential for femtosecond laser drilling in high-precision manufacturing applications.