What is optical isolation and why is it beneficial?

Optical isolation is a technique that protects electronic devices and circuits from ground loops, power surges, and electromagnetic interference. Duplicate ground references (ground loops) occur when there is more than one path to ground between connected devices. Ground loops can also happen when devices are connected to different power sources and there is a difference in the ground potential between the devices. Ground loops have a measurable voltage difference that is sometimes substantial and can generate enough current to damage sensitive electronic devices.

Optical isolation involves the use of optical isolators to transmit signals between two circuits while keeping them electrically isolated from each other. The basic principle of the practice is the conversion of electrical signals into optical signals, which are then transmitted through an optical medium such as an optical fiber or an air gap. The optical signal is received by a photodetector on the receiving side, which converts it back into an electrical signal.

The major benefit of optical isolation is its ability to provide complete electrical isolation between two circuits. This means that any electrical noise, ground potential differences, or power spikes present in one circuit will not be transferred to the other circuit. It prevents the passage of unwanted electrical currents, voltages, or transients between the isolated circuits.

Sealevel offers a wide range of digital & analog I/O adapters with optically isolated inputs, as well as serial I/O devices with optically isolated serial ports.