"Optical Spectroscopy" bridges a gap by providing a background on optics while focusing on spectroscopic methodologies, tools and instrumentations. The book introduces the most widely used steady-state and time-resolved spectroscopic techniques, makes comparisons between them, and provides the methodology for estimating the most important characteristics of the techniques such as sensitivity and time resolution. Recent developments in lasers, optics and electronics has had a significant impact on modern optical spectroscopic methods and instrumentations. Combining the newest lasers, advanced detectors and other high technology components researchers are able to assemble a spectroscopic instrument with characteristics that were hardly achievable a decade ago. This book will help readers to source spectroscopy tools to solve their problems by providing information on the most widely used methods while introducing readers to the principles of quantitative analysis of the application range for each methodology. In addition, background information is provided on optics, optical measurements and laser physics, which is of crucial importance for spectroscopic applications. It provides an overview of the most popular absorption/emission spectroscopy techniques. It discusses application range, advantages and disadvantages are compared for different spectroscopy methods. It provides introductions to the relevant topics such as optics and laser physics.