Neutrino astronomy is among the most promising fields for astro- and particle physics. Measuring astrophysical neutrinos and identifying their sources might shed light on the physics involved in the highest energy objects in the universe. However, measuring elusive neutrinos with large-volume telescopes requires high-precision understanding of the detector and its optical medium. The "Precision Optical Calibration Module" -- or POCAM -- is a novel calibration light source able to tackle the calibration of systematics within large-volume detectors. This isotropic, nanosecond, multi-wavelength light source is developed for the IceCube Upgrade and enables calibration of existing optical detector systematics down to a few percent. This work summarizes the efforts made in device development, the different calibration procedures and its potential physics impact in large-volume detectors. The latter is explicitly tested for IceCube Upgrade oscillation parameters.