Abstract

In order to create new possibilities of laser ablation technique, the laser ablation of nitrogen solid films (thickness: > 3 mm) on a Cu plate at 10 K was performed upon irradiation with a picosecond- UV laser (FHG of Nd:YLF laser; 263 nm, 8 ps, 10 Hz) in vacuum. UV and visible emissions, which were ascribed to the transition from excited molecular nitrogen (Vegard-Kaplan system; A-X transition) and atomic nitrogen (alpha emission: ²D - ⁴S transition at 523 nm), were detected on the film during the laser irradiation at the fluence of 5 J·cm^-2·pulse^-1 (Fig.1). These excited species would be produced on a multi-photon absorption process of the nitrogen by the ps-laser irradiation.

© 2000 IEEE