title: Wide-band six-region phase mask coronagraph.
abstract: An achromatic six-region phase mask coronagraph, used for the detection of exoplanets, is proposed. The mask has six regions in angular direction and could work in wideband. Furthermore, a six-level phase mask, as an example of the six-region phase mask, is theoretically investigated. According to numerical simulations, this specific mask has a deep elimination of starlight, good performance of achromatism and small inner working angle. As a single phase mask, the ratio of the remaining starlight of the six-level phase mask to the total incident starlight is less than 0.001 when the wavelength is between 500 nm and 600 nm.
authors: Fanzhen
authors: F
authors: Hou
authors: Qing
authors: Q
authors: Cao
authors: Minning
authors: M
authors: Zhu
authors: Ourui
authors: O
authors: Ma
mesh_terms: D000465:Algorithms; D001256:Astronomy / Q000295:instrumentation* / Q000379:methods*; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation* / Q000379:methods*; D016083:Planets; D014025:Titanium / Q000737:chemistry*
chemical_list: C009495:titanium dioxide; D014025:Titanium