  Instrumentation techniques in the field of direct imaging of exoplanets have
greatly advanced over the last two decades. Two of the four NASA-commissioned
large concept studies involve a high-contrast instrument for the imaging and
spectral characterization of exo-Earths from space: LUVOIR and HabEx. This
whitepaper describes the status of 8 optical testbeds in the US and France
currently in operation to experimentally validate the necessary technologies to
image exo-Earths from space. They explore two complementary axes of research:
(i) coronagraph designs and manufacturing and (ii) active wavefront correction
methods and technologies. Several instrument architectures are currently being
analyzed in parallel to provide more degrees of freedom for designing the
future coronagraphic instruments. The necessary level of performance has
already been demonstrated in-laboratory for clear off-axis telescopes
(HabEx-like) and important efforts are currently in development to reproduce
this accomplishment on segmented and/or on-axis telescopes (LUVOIR-like) over
the next two years.
