Book excerpt: The primary goal of this text book is to ensure that any physical science student, even one who has never heard of the subject, should be able to learn what ultrafast spectroscopy is, why optics related to the subject requires special attention, how to use the basic ideas of the subject in laboratory-based ultrafast spectroscopy experiments, how to interpret the experimental observations and so on. This book gives a more than adequate introduction to mathematical representation of an ultrafast pulse, chirp, time-band width product, nonlinear optical effects, dispersion effects, construction of ultrafast laser, ultrafast measurement techniques and different ultrafast processes of chemical interest.