Design and implementation of laser ablation device with a closed loop control method

This thesis investigates the effects of laser power and light intensity on microchannel formation on Polymethylmethacrylate (PMMA) material using a laser beam. A laser ablation device is designed and implemented with real-time beam power control to achieve this. Using this platform, a method is developed to regulate laser beam intensity by continuously measuring beam intensity distributions. A closed-loop control technique with a rule-based decision optimizes ablation quality. The controller generates a starting signal to laser power and motors based on ablation quality estimation. The quality of the ablation geometry is determined by image processing and inspection with a microscope. The laser machining process has been studied both theoretically and experimentally. The generated microchannels were analyzed in terms of ablation depth and shape. When the experimental results were compared with the theoretical calculations and simulations, it was observed that closed-loop control of laser beam power is an efficient technique for material etching and creating a smoother channel profile. As a result of the tests, the controller could intervene with feedback on the motor's speed and the laser beam's power.