Diagnostics and real-time monitoring of pulsed laser ablation

Signal generation, diagnostics and real-time monitoring during pulsed laser ablation of solid materials (silicon, metal and IC molding component) are investigated. It is found that there is rich signal emission in the laser ablation. Wide band microphone, ultrafast phototube and tiny metal probe are applied to detect acoustic, optical and electric signals generated during the laser ablation. Optical emission spectrum analyzer and high-speed ICCD photography are used to study laser-ablation-induced plasma dynamics. Signal variation with laser processing conditions during the laser ablation is analyzed. Formation of the signals is also discussed and modeled. Based on the signal diagnostics and analyses, relations between signal characteristic parameters and the laser processing conditions can be established for different applications of laser ablation in industry.