An optical amplifier is a device that amplifies an optical signal directly, without the need to first convert it to an electrical signal. An optical amplifier may be thought of as a laser without an optical cavity, or one in which feedback from the cavity is suppressed. Optical amplifiers are important in optical communication and laser physics.

Doped fibre amplifiers (DFAs) are optical amplifiers that use a doped optical fibre as a gain medium to amplify an optical signal. They are related to fibre lasers. The signal to be amplified and a pump laser are multiplexed into the doped fibre, and the signal is amplified through interaction with the doping ions. The most common example is the Erbium Doped Fibre Amplifier (EDFA), where the core of a silica fibre is doped with trivalent erbium ions and can be efficiently pumped with a laser at a wavelength of 980 nm or 1,480 nm, and exhibits gain in the 1,550 nm region.
An erbium-doped waveguide amplifier (EDWA) is an optical amplifier that uses a waveguide to boost an optical signal.
Amplification is achieved by stimulated emission of photons from dopant ions in the doped fibre. The pump laser excites ions into a higher energy from where they can decay via stimulated emission of a photon at the signal wavelength back to a lower energy level. The excited ions can also decay spontaneously (spontaneous emission) or even through nonradiative processes involving interactions with phonons of the glass matrix. These last two decay mechanisms compete with stimulated emission reducing the efficiency of light amplification.

GLSUN 1550nm CATV EDFA, for its high quality, high reliable and high cost performance, is the ideal choice of the system integration and system operation.

GLSUN High Power Erbium Doped Fiber Amplifier EDFA - Features 

1. The OLAH is a fiber amplifier and power supply integrated in a 1RU&2RU shelf.  Multiple output ports can be chose.
2. The OLAH incorporates electrical control circuitry wit a digital signal processor and includes photodiodes for monitoring the optical input and output power through tap couplers. 
3. Double cooling system can protect the pump laser to work in a long time.
4. RJ45 and RS 232 port, SNMP management system.
5. Good stability, VFD displays the working conditions, good trouble alarm system.