  KalAO is a natural guide star adaptive optics (AO) imager to be installed on
the second Nasmyth focus of the 1.2m Euler Swiss telescope in La Silla, Chile.
The initial design of the system is inspired on RoboAO with modifications in
order to operate in natural guide star (NGS) mode. KalAO was built to search
for binarity in planet hosting stars by following-up candidates primarily from
the TESS satellite survey. The optical design is optimised for the 450-900 nm
wavelength range and is fitted with SDSS \emph{g,r,i,z} filters. The system is
designed for wavefront control down to $I$-magnitude 11 stars in order to probe
the same parameter space as radial velocity instruments such as HARPS and
NIRPS. The principal components of the system are an 11x11 10.9 cm
sub-apertures Electron Multiplying CCD (EMCCD) Shack-Hartmann wavefront sensor,
a 140 actuators Microelectromechanical systems (MEMS) deformable mirror, a fast
tip/tilt mirror, and a graphics processing unit (GPU) powered glycol cooled
real-time computer. It is designed to run at up to 1.8kHz in order to detect
companions as close as the 150mas visible-light diffraction limit. The
real-time adaptive optics control is using the CACAO software running on GPUs.
The instrument is planned for commissioning early 2021 in Chile if the covid
restrictions are lifted.
