Smart laser ablation: An Arduino-based feedback for hand held laser delivery system

A novel feedback system has been developed in order to mechanize laser ablation processes such as laser cleaning. This is aimed at improving the safety and productivity (cleaned area/time) of the laser treatment in all those applications where the ablation process is not self-terminated. The system, which is devised as a stand-alone equipment that can be adapted to different laser sources, is based on the exploitation of the reflectance (R) measurements in a feedback loop for controlling a variable optical attenuator. Here, we demonstrate its effectiveness for controlling Nd:YAG (1064 nm) laser ablation treatments in conservation of cultural heritage. Pulse after pulse the reflectance trend can exhibit an increase, a drop, steadiness, depending on the outer material stratigraphy of the object. The feedback can be activated according to suitable discrimination criteria. We have used the Arduino Uno shield to interface the reflectance measurements to the PC and properly move an attenuator.