The Inner Environment of Protoplanetary Disks With Near‐infrared Spectro‐interferometry

In this paper, I review how optical spectro‐interferometry has become aparticularly well‐suited technique to study the close environment of young stars by spatially resolving both their infrared continuum and line emission regions. I summarize the ways optical interferometers have brought major insights about our understanding of the inner part of circumstellar disks, a region in which the first stages of planet formation are thought to occur. In particular, I emphasize how new methods are now enabling to probe the hot gas emission, in addition to the circumstellar dust.