Surface damage of silicon and copper by pulsed and pulse-periodic action of an Nd:YAG laser

An investigation was made of the damage to the surface of silicon and copper by pulsed and pulse-periodic action of an Nd:YAG laser. Anomalies were found in a probe Ne — He laser beam scattered by the surface of silicon when it was irradiated by a series of Nd:YAG pulses of I < I_melt intensity (I_melt is the surface melting threshold). These anomalies were attributed tentatively to the formation of a defect-saturated surface layer.