High-speed drilling of alumina ceramic by sub-microsecond pulsed thin disk laser

The rapid development of optoelectronic components has demanded high-speed drilling for alumina ceramic substrate. However, the existing drilling speed cannot meet the demand due to the limitation of conventional laser system and drilling method. In this paper, by adopting a sub-microsecond pulsed thin disk laser that based on a multi-pass pumping module, a laser system with a pulse energy of 37.4 mJ and a peak power of 103.8 kW is developed, which helps us to achieve high processing efficiency. In addition, experimental and theoretical analysis suggest the positive defocusing method can be used to control the hole taper angle, and micro-holes with a hole diameter difference less than 6% is realized, which helps us to achieve high processing quality. Ultimately, it is reported that the drilling speed for micro-holes with a diameter of ∼150 µm reaches 30 holes per second, and for micro-holes with a diameter of ∼100 µm reaches as high as 66 holes per second. The performance of the sub-microsecond pulsed thin disk laser presented in this paper provides a reference in the field of high-speed laser processing.