Galvanometer driven optical system for laser dynamic focusing

This paper proposes a novel dynamic focusing module driven by galvanometers to position the laser focus with high speed and high precision. Thanks to the extremely high repeatability and the fast response time of galvanometers, the repeatability of the laser focus positioning is far less than the Rayleigh length of the beam and its response time is around 600 µs. An important feature of the proposed module lies in that it can be further integrated to an XY galvo scanner to realize a 3-axis laser scanning system. Due to the same galvanometers of the dynamic focus module and the XY scanner, the laser focus could be positioned in a simultaneous, rapid and precise manner in all three axes. Various simulation and experimental results demonstrate the feasibility and performance of the proposed dynamic focus module and the processing capability of the 3-axis scanning system with the proposed module.