Optical isolators convert the input signal energy to light energy typically with a light-emitting diode (LED). The light energy is then converted back to electrical energy, typically with a photosensitive transistor, and then passed to the output.
The working of an optical isolator is based on optical isolation which is shown in figure 3.23. LEDs produce light when a voltage is applied across them.
The direction of the plane of polarization rotates is controlled by how the Faraday rotator affects the light beam. The change in the state of the light can be controlled precisely with a magnet.
An optical diode is another term given to a device capable of directing get in this way.
Noise levels are also reduced.