Radial-shearing interferometric imaging with Theon-Kepler bifocal telescope.

A method of radial-shearing interferometric imaging based on the Theon-Kepler bifocal telescope is proposed. The Theon-Kepler bifocal telescope system consists of two identical Theon photon sieves with bifocal spots. The short focal length of the first photon sieve coincides with the long focal length of the second photon sieve. At the same time, the first focal length coincides with the second short focal length. This setup naturally constitutes two sets of 4f systems. When a plane wave is incident on the bifocal telescope, two plane waves of different sizes are emitted. These two beams undergo radial-shearing interference. The common-path setup of this new type of radial-shearing interferometer is simple, with low requirements for the experimental environment and strong anti-interference ability. (C) 2020 Optical Society of America