Optics is generally defined as the scientific study of sight and the behavior of light, or the properties of transmission and deflection of other forms of radiation. The power of laser pulse is growing gradually every year due to development in ultra-short and ultra-intense laser technologies. Due to the easy accessibility of these new machines to researchers, experiments have witnessed total remodeling in non-linear optics. This is because an advanced physical picture of light matter correlation comes to fore whenever the laser pulse intensity approaches or exceeds intra-atomic field power. A very broad band of electromagnetic beam is ascertained when the laser rays are adeptly changed into fluxes of charged or neutral particles. The conservative phenomena of non-linear optics like harmonic generation, self-focusing, ionization, etc. exhibit widely contrasting reliance on laser pulse intensity in contrast to the established rules. This branch of research is developing at a rapid pace. The book imparts knowledge on the latest progress and testified results acquired by writers in some selected areas of this widespread domain of science. This book will provide information to readers who specialize in the subject of laser matter interactions.