The development of lasers emitting ultrafast pulses with durations of femtoseconds or picoseconds has opened up a range of spectroscopic applications in many disciplines. Based largely on the author’s graduate and training courses, this book offers a complete overview of the topic. After reviewing the unique properties of short pulses, it explores laser systems that create them as well as a range of novel spectroscopic applications and techniques. The text also includes online supporting material, such animations, computer programs, and applets.