The PAVO beam combiner has been operational at the CHARA array from 2008. The PAVO instrument is a 3-beam pupil-plane Fizeau beam combiner optimised for the highest possible sensitivity while also working at extremely high angular resolution. PAVO is one of the workhorse facility back-end instruments at the CHARA Array on Mt Wilson, Southern California. The CHARA interferometer boasts six 1m telescopes and the longest optical baselines (therefore highest resolution) available in the world (60% longer than VLTI). The PAVO instrument covers the short wavelength visible regime (from 0.6-0.9 microns) and is therefore the highest angular resolution instrument of its kind in operation. It successfully deployed a highly (at the time) innovative optical architecture, which enabled the measurement of the angular diameters of stars over a handful of spectral channels with unprecedented sensitivity and accuracy. PAVO’s enduring success is attested to by its longevity: it has served as the primary facility science instrument in its niche for more than a decade.
