Partially Overlapped Dual Laser Beams to Reduce Ablation Craters**Supported by the National Natural Science Foundation of China under Grant Nos 61525503 and 41603059, the National Key Research and Development Project of China under Grant No 2016YFC14000701, and the Shenzhen Basic Research Project (JCY20160428092445411).

Abstract

We present our experimental ablation results for partially overlapped dual nanosecond laser beams (PO-DB) on metal and glass surfaces. Numerical simulations are performed to evaluate the crater reduction potential of the PO-DB setup. Damage probability experiments proved the collaboration of two beams within the overlap region. Bright-field and three-dimensional profile measurements verify the reduced ablation area from the proposed PO-DB scheme. Laser-induced plasma is generated when transparent glass is ablated. Atomic emission of Na I (∼589.95 nm) shows comparable signal between the PO-DB set and the traditional single laser beam set. The proposed PO-DB ablation mechanism could also be applied to femtosecond laser systems.