  In the era of high-angular resolution astronomical instrumentation, where
long and very long baseline interferometers (constituted by many, $\sim$ 20 or
more, telescopes) are expected to work not only in the millimeter and
submillimeter domain, but also at near and mid infrared wavelengths
(experiments such as the Planet Formation Imager, PFI, see Monnier et al. 2018
for an update on its design); any promising strategy to alleviate the costs of
the individual telescopes involved needs to be explored. In a recent
collaboration between engineers, experimental physicists and astronomers in
Valparaiso, Chile, we are gaining expertise in the production of light carbon
fiber polymer reinforced mirrors. The working principle consists in replicating
a glass, or other substrate, mandrel surface with the mirrored adequate
curvature, surface characteristics and general shape. Once the carbon fiber
base has hardened, previous studies have shown that it can be coated (aluminum)
using standard coating processes/techniques designed for glass-based mirrors.
The resulting surface quality is highly dependent on the temperature and
humidity control among other variables. Current efforts are focused on
improving the smoothness of the resulting surfaces to meet near/mid infrared
specifications, overcoming, among others, possible deteriorations derived from
the replication process. In a second step, at the validation and quality
control stage, the mirrors are characterized using simple/traditional tools
like spherometers (down to micron precision), but also an optical bench with a
Shack-Hartman wavefront sensor. This research line is developed in parallel
with a more classical glass-based approach, and in both cases we are
prototyping at the small scale of few tens of cms. We here present our progress
on these two approaches.
