Improved absorption spectroscopy with pulsed lasers

A simple formalism is given to allow for intensity correction and background suppression in absorption spectroscopy with pulsed lasers. By experimental examples the online application with a microcomputer is demonstrated, and the computer is also used for analyzing the correlation between signal and reference channels. The optimization of the correlation and the intensity correction yields a gain of a factor of about 30 in the signal-tonoise ratio of the recorded spectra compared to conventional absorption experiments. Spectral lines were observed, which would not be detectable by fluorescence technique.