Abstract

The renaissance of photo-acoustic spectroscopy {1} has recently led to several novel forms of imaging. Common to all of these is the use of a modulated laser (or electron) beam which is partially absorbed by the object to be imaged. The energy from the incident beam is transformed, with varying degrees of efficiency, into thermal energy giving rise to stress waves within the object, producing pressure changes in the adjacent air, and I.R. radiation from the object. All of these effects have been successfully used as the basis of imaging systems, {2, 3, 4}.

© 1981 Optical Society of America