Recently, researchers at Shanghai Institute of Optics and Fine Mechanics of the Chinese Academy of Sciences have proposed a new kind of telescope structure, a Theon-Kepler bifocal telescope, to realize radial-shearing interferometry in common-path setup. This research has been published in Applied Optics.
Click here for original story, Theon-Kepler bifocal telescope helps advance radial-shearing interferometry
Source: Phys.org