Ultrafast and High-Precision Steering of Laser Beams: Using a Synchronized Scanning System with Frequency Domain Feedforward Tuning

Beam steering plays a pivotal role in laser manufacturing, where the deflection range, response time, and precision of beam steering significantly affect the scale, throughput, and quality of manufacturing. Recent advancements in beam steering focus on integrating galvanometer scanners with acousto-optic deflectors (AODs), thereby achieving both large deflection angles and ultrafast response time. To further enhance steering precision, it is effective to utilize AODs for correcting the errors of galvanometer scanners in real-time. Nevertheless, a challenge arises in keeping tracking error of galvanometers within the deflection range of AODs across general high-speed trajectories. To tackle this challenge, this paper proposes a frequency domain iterative feedforward tuning method aimed at enhancing the general tracking precision of galvanometers. Furthermore, a synchronized scanning system, where AODs could effectively reduce tracking error of galvanometers, is implemented with the proposed method. Experimental results validate that the proposed control method exhibits superior extrapolation capability compared to the existing feedforward tuning approach across various trajectories characterized by significant differences in spectrum.