Nulling interferometry

Nulling interferometry consists of causing a phase difference of half a wavelength in the beams of light collected by two telescopes, in order to eclipse the light from an object situated on the optical axis and thus render visible anything that is slightly to the side. This technology could soon be used in space research for exoplanets: nulling interferometry allows the stars signal to be blocked out in order to reveal a possible planetary companion. Furthermore, by playing on the distance between the telescopes, it is possible to choose the wavelength at which the transmission is at its maximum to study the planet.