"Cavity-Enhanced Spectroscopy" discusses the use of optical resonators and lasers to make sensitive spectroscopic measurements. This volume is written by the researcchers who pioneered these methods. The book reviews both the theory and practice behind these spectroscopic tools and discusses the scientific discoveries uncovered by these techniques. It begins with a chapter on the use of optical resonators for frequency stabilization of lasers, which is followed by in-depth chapters discussing cavity ring-down spectroscopy, frequency-modulated, cavity-enhanced spectroscopy, intracavity spectroscopies, microresonators and cavity-enhanced comb filters. This book is aimed towards a reader with a background in optics and spectroscopy, but who is unfamiliar with the methods discussed in the book. *Practical implementation informationComprehensive review of cavity-enhanced methods*Written by the researchers who pioneered these spectroscopies*Discusses cavity-enhanced optical instrumentationReviews scientific discoveries unearthed using these methods