Since the development of the laser, beginning only about 12 years ago, the conduct of the entire field of spectroscopy has undergone major and far-reaching changes. The laser is far more than just an improved light source; its impact has rather been qualitative, in the same way that the development of nuclear magnetic resonance has altered the conduct of synthetic organic chemistry, or as the digital computer has made modern systems analysis possible. Some indication of this impact may be gained from the increase in the number of articles published in the Journal of Chemical Physics which make experimental use of lasers, or deal directly with laser problems; this is shown, for the period 1963-1974, in Figure 1 (following page). Since this particular journal is a basic one in its field, not particularly devoted to new developments in quantum electronics, the increase shown is a good measure of the extent to which laser techniques have permeated such classical areas as molecular spectroscopy and reaction dynamics. Following an induction period of several years, in which the technology was developed by physicists and electrical engineers and filtered down from these to chemists and spectroscopists, the usage of lasers showed a sharp increase - far more than could be accounted for simply by an increase in the overall volume of publications - until today 60 to 90 laser-related articles appear in each semi-annual volume of this journal alone.