Describe 'active' optical devices in the context of fiber optics.

In the context of fiber optics, 'active' optical devices refer to those components that require an external power source to perform their functions. This includes devices that amplify signals, convert signals from one form to another, or generate light. Examples of active optical devices are lasers, which emit light that can be transmitted through optical fibers, and optical amplifiers, which boost weak signals traveling through fiber optic cables.

The importance of active optical devices lies in their ability to maintain signal integrity over long distances. They play a crucial role in various applications, including telecommunications, where the loss of signal strength can occur due to attenuation in the fiber. By amplifying the signal or converting it into a more suitable form, these devices help ensure that data can be transmitted efficiently and with high fidelity over extensive networks.