EDFA play important role in optical communication networks, It provides high output power, high gain, wide frequency bandwidth, low power input, and low noise. This article will share some knowledge about EDFA.

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EDFA play important role in optical communication networks, It provides high output power, high gain,
wide frequency bandwidth, low power input, and low noise. This article will share some knowledge about
EDFA.
What is EDFA?
An erbium-doped fiber amplifier (EDFA) is an optical repeater device that boosts the power of
optical signals sent across fiber optic cables. An optical fiber is doped with the rare earth element
erbium so that the glass fiber can absorb and emit light at another frequency.
An EDFA uses the erbium-doped fiber as an optical amplification medium to enhance the signals
directly. In addition, an EDFA can amplify multiple optical signals simultaneously and easily
combined with WDM technology, which is used in the C band and L band in the range from 1530

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to 1565 nm.
How Does an EDFA Work?
An EDFA consists of a length of Erbium-doped fiber (EDF), a pump laser, and a WDM combiner.
The WDM combiner is for combining the signal and pump wavelength so that they can propagate
simultaneously through the EDF.
The optical signal (1550nm) enters an EDFA from the input, and the 1550nm signal is combined
with a 980nm pump laser and WDM device. The signal and the pump laser pass through a length
of fiber doped with Erbium ions, and the 1550nm signal is amplified through interaction with the
doping Erbium ions. This action amplifies a weak optical signal to a higher power, which boosts
the signal strength.
EDFA Types
 Booster Amplifier

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A booster amplifier EDFA operates at the transmission side of the DWDM link. It amplifies the
multiplexed optical signals before sending them into an optical fiber. The common types of OBA
are 20dBm Output C-band 40 channels 26dB gain booster EDFA and 16dBm output C-band 40
channels 14dB gain booster EDFA.
 Pre-amplifier
A pre-amplifier EDFA operates at the receiving end of a DWDM link. It is used to compensate for
losses in a de-multiplexer near the optical receiver.
 Line Amplifier
A line amplifier EDFA is generally set at intermediate points along the transmission link in a
DWDM link to overcome fiber transmission and other distribution losses. It is designed for optical
amplification between two network nodes on the main optical link. The typical distance between
each line of the amplifier EDFA is 40 km, 60km, 80km, and 100km.
Features and Benefits
EDFA provides low optic power input, high optic power output, high optical gain, high stability,
wide frequency bandwidth, VFD or LED displays the working conditions and trouble alarm, RJ45
port for SNMP remote management, and RS232 for local management, low noise, low loss, and
easy to deploy.
Applications
EDFA is used in FTTH, WDM(DWDM), cable television distribution networks, optical digital
communication, long-haul optical communication system, optical subscriber access network
system, distribution network, etc.

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Conclusion
As EDFA performs as the most widely used optical amplifier, it also proves to be the most
advanced one that holds the dominant position in the market. With the deployment of WDM
systems and the increasing aggregate bandwidth of optical fibers, the WDM system integrated
with EDFA will gain more benefits. Sun Telecom specializes in providing one-stop total fiber optic
solutions for all fiber optic application industries worldwide. Contact us if any needs.