Fast-steering two-axis tilt mirror for laser pointing and scanning

摘要

Abstract: Compact fast-steering two axis-tilt mirrors are key components in astronomy, laser communications, material processing applications, imaging systems, biomedical and ophthalmologic applications. The laser scanner presented in this paper can perform a variety of functions such as tracking, beam stabilization and alignment, pointing and scanning. The small overall volume of 30 $MUL 40 $MUL 50 mm$+3$/ can lead to a very stable and compact system design. The fact that the steered mirror has a single point of rotation for the two tilt axes is a clear advantage for systems with scanning lenses designed for this purpose. The scanner is composed of one single mirror driven by two pairs of push-pull linear electromagnetic actuators. The suspension of the mirror is based on a cone-ball bearing with optimized friction and wear behavior. A Position Sensitive Detector integrated in the module is used for the closed loop feedback positioning. The mirror can be tilted by more than $POM 52 mrad ($POM@3$DGR@) with an accuracy better than 50 $mu@rad. A differential resolution of the order of 5 $mu@rad and a settling time for maximum deflection of 9 ms is achieved. Due to the large active area of the mirror (30 mm $MUL 40 mm), very small spot diameters can be reached (less than 1 $mu@m) using high quality laser beams. Therefore, the scanner can be used e.g. in high precision micro-material processing of semiconductor and sensor industry.!13