Pulsed photoelectron microscope for imaging laser-induced nanosecond processes

A flash photoelectron microscope, driven by 4 ns KrF excimer laser pulses, is introduced. The microscope is equipped with a solid state laser for in situ processing of metals with focused nanosecond pulses. Transient stages during laser-induced melting, solidification, and alloying of Al films on bulk substrates have been imaged with an exposure time of 4 ns. The photoelectron microscope is proved to be a powerful real-time probe for fast-proceeding incipient laser-induced damage, sensing changes of surfaces being too shallow to be detected by light interference and electron scanning microscopy. The combined time/space resolution is limited by lens aberrations, space charge, shot noise, and detector efficiency to about 4 ns/1.3 mu m, at present. (C) 1997 American Institute of Physics.