Air Lasing Preface 1 Diagnostic properties of two photon pumped stimulated emission in atmospheric species 2 High gain air lasing by multi photon pumping of atomic species 3 The role of electron collisions in lasing in neutral and singly ionized molecular nitrogen 4 Molecular rotational effects in free space N_2^+ lasers induced by strong field ionization 5 Filament initiated lasing in neutral molecular nitrogen 6 Filament assisted impulsive Raman spectroscopy Index. This book presents the first comprehensive interdisciplinary review of the rapidly developing field of air lasing. In most applications of lasers such as cutting and engraving the laser source is brought to the point of service where the laser beam is needed to perform its function. However in some important applications such as remote atmospheric sensing placing the laser at a convenient location is not an option. Current sensing schemes rely on the detection of weak backscattering of ground based forward propagating optical probes and possess limited sensitivity. The concept of air lasing (or atmospheric lasing) relies on the idea that the constituents of the air itself can be used as an active laser medium creating a backward propagating impulsive laser like radiation emanating from a remote location in the atmosphere. This book provides important insights into the current state of development of air lasing and its applications.