When the laser was invented one and a half decades ago it became
obvious at once that this new device would be a unique light source
for many spectroscopic applications. Spectroscopists were initially
engaged in looking for new laser materials having transitions suitable for
laser action. Many new optical transitions were found in this way and a
large amount of new spectroscopic data especially in the infrared
spectral region was gathered.
Concurrently the interaction of intense laser radiation with matter
was investigated, and many nonlinear effects explored. At the same time
useful spectroscopic information was obtained by studying Raman
spectra in solids, liquids and gases, using the laser as source of intense
light.