Results from Cryo-PoF: Power over fiber for fundamental and applied physics at cryogenic temperature

The Power over Fiber (PoF) technology delivers electrical power by sending laser light through an optical fiber to a photovoltaic power converter, in order to power sensors or electrical devices. This solution offers several advantages: removal of noise induced by power lines, robustness in a hostile environment, spark free operation when electric fields are present and no interference with electromagnetic fields. This technology is at the basis of the Cryo-PoF project: an R&D funded by the Italian Institute for Nuclear Research (INFN) in Milano-Bicocca (Italy). This project is inspired by the needs of the DUNE Vertical Drift detector, where the VUV light of liquid argon must be collected at the cathode, i.e. on a surface whose voltage exceeds 300 kV. We developed a cryogenic system, which is solely based on optoelectronic devices and a single laser input line, to power both the Photon Detection devices and its electronic amplifier. The Milano-Bicocca setup employ a commercial GaAs laser source with 2 W maximum power and a photovoltaic power converter with efficiency of 30% at liquid nitrogen temperature. The results obtained in Milano Bicocca will be presented with emphasis on performance and potential application in the field of applied physics.