Book excerpt: A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term "e;laser"e; originated as an acronym for "e;light amplification by stimulated emission of radiation"e;. Laser Applications provides a firm grounding in the fundamental concepts over governing the field on Optics. This reference book is useful for the students of B.E., B.Tech. and M.Tech., courses. The present book is an attempt to treat the subject of Laser as an introductory course. With recent major breakthroughs in ultrafast laser technology and femtosecond nonlinear spectroscopic techiques, Femtosecond Laser Spectroscopy is currently a burgeoning field in many branches of science, including physics, chemistry, biology, and materials science. Attempts have also been made to cover the frontline areas in the subject. The development of Laser and its various applications in Communications, Radiation, medicine, Holography etc., has been given due importance.