  Power-over-Fiber (PoF) technology has been used extensively in settings where
high voltages require isolation from ground. In a novel application of PoF,
power is provided to photon detector modules located on a surface at $\sim$ 300
kV with respect to ground in the planned DUNE experiment. In cryogenic
environments, PoF offers a reliable means of power transmission, leveraging
optical fibers to transfer power with minimal system degradation. PoF
technology excels in maintaining low noise levels when delivering power to
sensitive electronic systems operating in extreme temperatures and high voltage
environments. This paper presents the R$\&$D effort of PoF in extreme
conditions and underscores its capacity to revolutionize power delivery and
management in critical applications, offering a dependable solution with low
noise, optimal efficiency, and superior isolation.
