An active device is a device used in optical communication that requires a source of electrical energy for its operation. The energy is typically provided by a battery or by an electrical circuit connected to a power supply. Batteries recharged by wind or solar energy are beneficial to the network owners. to the Active device has an output that is a function of present and past input signals.
There are many different types of components used for communication. All these components fall under two categories, fiber optic active components and fiber optic passive components. The fiber passive components, which require no input power to function, include but are not limited to such devices asoptical fiber cable, fiber optic connectors, cabinets, splice closures, distribution frames etc.
Active device is any type of component having an electrical circuit. The development of optical communication requires higher rate, larger capacity devices, while the cost is lower, which rely on photonic integrated circuit (PIC).
Main optical devices in an optical network are:
1). Optical passive devices, including optical fiber jumper, connector, plug, fixed attenuator, adapter, divider, isolator, coupler, dielectric film filter and optical fiber grating filter, optical switch, wavelength division multiplexing(WDM CWDM DWDM) and so on. These devices are generally used to split and combine signals, or alter them in various other manners.
2). Optical active devices, including optical sending and receiving module, amplifier, electrical adjustable attenuator.
Examples of active device include controlled power supplies, transistors, LEDs, amplifiers, and transmitters. Commonly used in fiber optics to refer to the transmitter/transceiver and/or detector of the optical network, these devices can be known as either electro-optical or opto-electrical devices and consist of laser or LED diode transmitters, amplifiers, APD (avalanche photodiode) or PIN (positive intrinsic negative) diode detectors. These devices are responsible for converting both analog and digital signals to and from optical pulses transported over the optical fiber network.
Presence of active devices in a network calls for special attention, especially when there is a breakdown related to the active device. Periodic maintenance and performance checks shall be done to ensure uninterruptible service by the network. Maintenance of active needs to be done by trained staff, and such expenses are included in the operational cost of the network. Therefore network designers take care to place all the possible active devices in common locations along the network.