It is over a decade since picosecond laser pulses were first produced by passive modelocking of a giant-pulse ruby laser by Mocker and Collins [2.1] in 1965 and then Nd: glass lasers by DeMaria et al. [2.2] in 1966. Since then the techniques for the generation of these pulses have been developed to the extent that it is possible to reliably produce pulses of bandwidth-limited durations of — 1 ps from both pulsed and cw lasers. In addition, theoretical models have been refined to the stage that there is excellent agreement with even the details of the experimental results, and there is now a very good understanding of the mechanisms by which ultrashort pulses evolve from the initial fluorescence intensity fluctuation patterns. These substantial advances in technology and physical understanding have been largely due to the simultaneous development of the methods of picosecond chronoscopy, particularly the direct linear measurement of pulse durations by electron-optical streak cameras. This pattern, of course, follows the historical pattern whereby developments in science and technology are almost always related to advances in measurement techniques. As a result the methods of picosecond laser pulse generation and measurement are now sufficiently refined and catalogued for them to be used with confidence for the investigation on a picosecond timescale of the interaction of coherent light with matter.