The polarization issue in optical long baseline interferometry

Abstract
One major technical hurdle that has to date been neglected in optical interferometry is measurement of polarization of light. However, thanks to pioneering works in the last decade, the interest of adding a polarimetric equipment has now been recognized. In this paper, I present a short overview of the astrophysical opportunities offered by optical polar-interferometry, but also a historical review of the already achieved instrumental steps.