Photonic mid-infrared nulling for exoplanet detection on a planar
  chalcogenide platform
  The future of exoplanet detection lies in the mid-infrared (MIR). The MIR
region contains the blackbody peak of both hot and habitable zone exoplanets,
making the contrast between starlight and planet light less extreme. It is also
the region where prominent chemical signatures indicative of life exist, such
as ozone at 9.7 microns. At a wavelength of 4 microns the difference in
emission between an Earth-like planet and a star like our own is 80 dB. However
a jovian planet, at the same separation exhibits 60 dB of contrast, or only 20
dB if it is hot due to its formation energy or being close to its host star. A
two dimensional nulling interferometer, made with chalcogenide glass, has been
measured to produce a null of 20 dB, limited by scattered light. Measures to
increase the null depth to the theoretical limit of 60 dB are discussed.
