Spectroscopy in its broadest sense deals with the interaction of light with matter. Spectroscopic techniques contribute a lot to various diverse research areas including material processing and characterisation, communication, forensic science, defence, etc. The rapid expansion of research activity in the field of material science evokes the need for different analytical and diagnostic techniques. Spectroscopy is such an analytical and diagnostic tool, extremely used to characterise materials. It is now commonly used by astrophysicist, mineralogists, nano-physicists or even scientists working in medical research. This book has therefore been prepared to provide easy access to basic information on different spectroscopy techniques and related instrumentation. This book is intended as a guide to the novice reading technical books or facing the complexities while dealing with the concept of spectroscopic techniques and their instrumentation. The authors of chapters presented in this book are all experts in their fields and were instructed to give substantial information to enable novices to learn and understand the advanced spectroscopic techniques. The present book primarily provides details about the time resolved spectroscopy; laser induced breakdown spectroscopy (LIBS); Raman spectroscopy; nonlinear spectroscopy; microwave spectroscopy; up conversion spectroscopy, etc