This book builds on the foundation laid by Optical Fiber Sensor Technology, Volumes I, II, and III. In Volumes I and II the material covered encompassed the fundamentals and underlying principles of the subject and the progress in devices and their associated technology which has taken place in recent years. Volume III and Optical Fiber Sensor Technology Volume IV concentrate on the applications of the technology and systems that rely upon it. This volume has a particular emphasis upon environmental sensing covering topics such as chemical and sol-gel based fiber optic sensors, fiber optic luminescent thermometry, liquid crystals in optical fiber sensors and biomedical application of fiber optic sensors. Edited by two scientists with a wide knowledge of the field and the community, the book brings together leading academics and practitioners in a comprehensive and incisive treatment of the subject. This is an essential reference both for researchers working and teaching in optical fiber sensor technology and for industrial users who need to be aware of current developments in optical fiber sensor devices and new areas of the associated technology.