Commercial laser power converters for power-over-fiber with Watts of output power capabilities over kilometers

We demonstrate the use of laser diodes and multijunction photovoltaic power converters to efficiently deliver watts of electrical power for long-distance. Transmission through single-mode and multi-mode fibers at the wavelengths of 808nm and 1470/1550 nm are studied. An electrical output power of ~0.1W is obtained after a 5km transmission through a standard single-mode SMF28 fiber fed with 0.25W of optical power. An electrical output power of ~1W is demonstrated after a 5 km transmission with a standard OM1 multi-mode fiber fed with ~2.5W. Photovoltaic conversion efficiencies reaching Eff ~49% are obtained with an output voltage of ~5V using commercial multijunction laser power converters. Furthermore, for specialized applications, a cryogenic power-over-fiber system at ~1470nm is demonstrated with ~2W of electrical power converted over a 10m distance having a conversion efficiency of Eff > 65% at 77K.