Optical imaging is a pillar in biomedical research from super-resolution microscopy to whole-body imaging in animal models. Optical imaging covers such a large field that it is difficult to decide what was the first medical application .Could it be said that the introduction of spectacles in 1270, in Florence, Italy was the first use of optical imaging in medicine? Or the introduction in 1590 of the compound microscope by the father and son team of Hans and Zacharias Janssen in the Netherlands? It is more likely that optical imaging (as understood by the general scientific community) and the application of biomedical optics to diagnose various diseases, came to prominence with the discovery of optical coherence tomography (OCT) in the 1990s, although there had been a variety of fluorescence and other simple optical imaging techniques being sporadically explored for many years earlier. Now there are many sophisticated optical imaging methodologies being studied and explored for diagnosis, such as in vivo confocal microscopy, optical frequency domain imaging , diffuse optical imaging , fluorescence tomography , Brillouin microscopy , Cerenkov imaging , polarization sensitive techniques , photoacoustic techniques , and so on.

In the present book, fifteen typical literatures about advances in optical imaging technique published on international authoritative journals were selected to introduce the worldwide newest progress, which contains reviews or original researches on optical imaging technique, optical coherence tomography and sophisticated optical imaging methodologies, etc. We hope this book can demonstrate advances in optical imaging technique as well as give references to the researchers, students and other related people.