Fiber optic network


A fiber optic network is much better than an Ethernet cable in terms of electromagnetic emissions. The fiber optic cable is completely free of any EMF since it is made of plastic or glass, and it doesn't carry any electric current or electric charge, from the macroscopic point of view, so the electric field and the magnetic field around the cable are zero at all frequencies. Another important advantage of a fiber optic link is that it isolates the devices, it doesn't carry the electromagnetic noise from one device to the other. The devices at the ends of the fiber optic cable instead have some electromagnetic emissions, but if they are shielded well and are kept far enough from ourselves, they can be used. Previously we presented the Plastic Optical Fiber system or POF, which is pretty good. Here we suggest another type of products that are still fiber optic and can be even better than the POF for some reasons.

Fiber optic network converters

Each fiber optic network link requires two fiber optic network converters and one fiber optic cable. The fiber optic network converter has a standard Ethernet connector (RJ45) and a fiber optic connector. For example a fiber optic converter would be connected to a computer by means of a short Cat5 cable, and another would be connected to an Ethernet router by another short Cat5 cable. These fiber optic converters need a DC power, usually it is 5V DC. Since the power required is small it can be provided by a USB port of the computer, or the router. Otherwise we have to use a 5V DC power supply.

These products are sold with a 5V DC power adapter, which as usual, is a SMPS, and so creates some electromagnetic noise, and radiation. It would be better to use a linear power supply, but linear power supplies are much bigger and more expensive. However a single linear power supply could provide the DC power to a group of devices.

There are two classes of these devices, those that support 100 Mbps and those that support 1 Gbps. For a typical office 100 Mbps are surely enough. Also, if the internet connection of the office is a DSL that works at most at 20 Mbps, there's no advantage in having a local network link at 1 Gbps. The higher speed can be useful if we need to connect two or more computers in the same office.

The fiber optic Ethernet converters usually have already a metal enclosure, which is good for shielding the electromagnetic emissions of the circuits. However these enclosures usually have a series of slots on one side or on two sides, and these slots cause some EM radiation to escape. Usually these slots can be covered with aluminum tape without causing problems to the circuits. If the circuit box become too hot, then probably it is better to move it in a cooler room.

Fiber optic cable

The fiber optic cable used in this system is very thin and flexible, just 3 mm thick. Like all fiber optic cables it can't be bent too much otherwise the fiber inside would be deformed irreparably. However this cable is flexible enough to follow the corners of the walls. This cable is also easily damaged by heat, so it has to be installed far enough from any object that may become hot, like hot water pipes, incandescent light bulbs etc....

These cables are sold already assembled with the connectors so they can't be cut at the desired length. There are usually offers of cables of various lengths, like 3m, 5m, 10m, 15m, 20m, 30m, 50m. There are also many different types of fiber optic cables and connectors. The cable has to be compatible with the terminal device.

The fiber optic connector is a delicate spot that has to be protected from the dust. The actual optical fiber is very thin, so a speck of dust could cause problems. So it is better to keep always the cap on the connector when the connector is not attached to another connector.

Comparison with POF

In comparison with the Plastic Optical Fiber system, this system is much less expensive, these products are not expensive at all, the fiber optic converters may cost 10 - 15 USD each and a 20 m cable may cost 10 USD. This fiber optic cable is also more flexible than the POF cable, and the fiber optic Ethernet converters already have a metal enclosure which is a partial shielding.

These fiber optic Ethernet converters however are bigger than the POF ones, and these fiber optic cables have connectors and they can't be cut at the desired length. Finally, we haven't found any PCI network card for desktop computers compatible with this system.


In conclusion this set of products for creating a fiber optic link between two computers or a computer and a router, is a good solution for reducing the electromagnetic fields and radiation. Click on the pictures to read more details about these components.

Media converter
Power adapter
USB power
Cat5 patch
Media converter mini
Media converter small
Wall plates
Mounting box
Mounting box example
Wall box example

Design service

If you want to install a fiber optic network in your office we can help you by providing all the needed information to find the products online at the best prices. We can also design the system and check the layout, and provide a detailed guide for the setup. For more information send us a message.