Accuracy control of three-dimensional Nd:YAG laser shaping by ablation

Improving the dimensional accuracy along the optical axis without decreasing the materials removing rate is a key issue in three-dimensional laser shaping. This paper presents a concept for performing three-dimensional laser shaping by directly using machining laser as the photo source of the non-contacting measuring device. Due to the high power measuring photo sourer and a 1.06 mu m bandpass filter. the interference caused by the emission light of ablated surface can be effectively avoided, the delay time is not needed to be inserted between the laser pulse and the measurement. So the measurement will not decrease the material removal rate and productivity. By using this system, the shaping accuracy of 30 mu m can be achieved at the removing rate of about 4.0 x 10(-2) mm(3)/sec for Si3N4 ceramic, both are much better than the results obtained before. (C) 2000 Elsevier Science Ltd. All rights reserved.