Delivering power over fibre optics

Engineers at Sandia National Laboratories in the U.S. are developing power-over-fibre (PoF) communications cabling, with total electrical isolation. Fibre optic cables are commonly used to isolate communications between systems or devices. However, when power is needed, it is usually sent down a copper wire. However, this can pose a safety problem. Battery power as an alternative is not always suitable or practical.

Now, engineers at the labs have come up with a first-generation power-over-fibre cable that converts a signal from electrical-to-optical-to-electrical, thus emulating an electrical cable in total isolation.

Optical interface circuits integrated into the connector housing provide fibre optic transmission of both data communications and optical power. This means the cable is safe to use in rigorous applications like security, explosives, explosion-proof devices, aviation and medical devices. Of course, power-over-fibre has power limitations since the electricity is optically generated. It cannot be used in applications that require anything more than low power, but is ideal for low-power sensor and control applications.

The first version of the cable includes circular stacked circuit boards with LEDs coupled to plastic optical fibres for communications, and a laser diode and miniaturized photovoltaic-type cell coupled to the ends of a single glass fibre to deliver optical power.


This story was originally posted in Electronics News.


Sandia National Laboratories