Tag Archives: Optical Fiber Amplifier

Technology Of Fiber Optic Amplifiers


In fiber optic communication, the visible-light or infrared (IR) beams carried by a fiber are attenuated as they travel through the material. Then there comes to the fiber optic amplifier which is used to compensate for the wakening of information during the transmission.

Amplifiers are inserted at specific places to boost optical signals in a system where the signals are weak. This boost allows the signals to be successfully transmitted through the remaining cable length. In large networks, a long series of optical fiber amplifiers are placed in a sequence along the entire network link.

Common fiber optical amplifiers include Erbium-Doped Fiber Amplifier (or EDFA Amplifier), Raman fiber amplifier, and silicon optical amplifier (SOA). Erbium doped fiber amplifier is the major type of the fiber amplifier used to boost the signal in the WDM fiber optic system, as we know it is WDM that increase the capacity of the fiber communications system and it is the erbium-doped fiber amplifier that makes WDM transmission possible. Fiber amplifiers are developed to support Dense Wavelength Division Multiplexing (DWDM) which is called DWDM EDFA amplifier and to expand to the other wavelength bands supported by fiber optics.

There are several different physical mechanisms that can be used to amplify a light signal, which correspond to the major types of optical amplifiers. In doped fibre amplifiers and bulk lasers, stimulated emission in the amplifier’s gain medium causes amplification of incoming light. In semiconductor optical amplifiers (SOAs), electron-hole recombination occurs. In Raman amplifiers, Raman scattering of incoming light with phonons in the lattice of the gain medium produces photons coherent with the incoming photons. Parametric amplifiers use parametric amplification.

When light is transmitted through matter, part of the light is scattered in random directions. A small part of the scattered light has frequencies removed from the frequency of the incident beam by quantities equal to the vibration frequencies of the material scattering system. Raman fiber optic amplifiers function within this small scattering range. If the initial beam is sufficiently intense and monochromatic, a threshold can be reached beyond which light at the Raman frequencies is amplified, builds up strongly, and generally exhibits the characteristics of stimulated emission. This is called the stimulated or coherent Raman effect.

EFDA fiber optic amplifier functions by adding erbium, rare earth ions, to the fiber core material as a dopant; typically in levels of a few hundred parts per million. The fiber is highly transparent at the erbium lasing wavelength of two to nine microns. When pumped by a laser diode, optical gain is created, and amplification occurs.

Silicon or semiconductor optical amplifier functions in a similar way to a basic laser. The structure is much the same, with two specially designed slabs of semiconductor material on top of each other, with another material in between them forming the “active layer”. An electrical current is set running through the device in order to excite electrons which can then fall back to the non-excited ground state and give out photons. Incoming optical signal stimulates emission of light at its own wavelength.

Fiber optic repeater also can re-amplify an attenuated signal but it can only function on a specific wavelength and is not suitable for WDM systems. That is the reason why optical fiber amplifier plays a much more important role in communication systems.

Overview Optical Fiber Amplifier From Fiberstore


The Optical Amplifiers are devices that direct the amplified light signal, without the need to first convert it into an electrical signal. Prior to this, the transmission signal amplification to achieve the photoelectric conversion and electro-optical conversion, i.e., O / E / O converting. With the optical amplifier can achieve optical signal amplification. The successful development of the optical amplifier and its industrialization is a very important achievement in the optical fiber communication technology, it has greatly contributed to the development of optical multiplexing, optical soliton communication and all-optical network.

Fiber amplifier will not only directly amplifying optical signals, and also offers real-time, high gain, broadband, online, low noise, low loss optical zoom function is the key components of a new generation of optical fiber communication systems essential. The Fiber Amplifier Usually by the gain medium, the pumping light input-output coupling structure and composition. Fiber amplifier mainly erbium-doped fiber amplifier, semiconductor optical amplifiers and three optical fiber Raman amplifier according to the position and the role of the fiber amplifier in the optical fiber line relay amplification, generally divided into three pre-amplification and power amplification.

Optical Fiber Amplifier(OFA) is used in optical fiber communication lines, to achieve a new all-optical signal amplification amplifier. Erbium-doped fiber amplifier (EDFA), semiconductor optical amplifier (SOA) and optical fiber Raman amplifier (FRA), erbium-doped fiber amplifier with its superior performance in practical fiber amplifier is now widely used in long distance, high-capacity, high-speed optical fiber communication systems, access networks, optical fiber CATV networks, military systems (radar multi-channel data multiplexing, data transmission, guidance, etc.) in areas such as power amplifiers, repeaters amplifier and preamplifier .

Coexistence of CATV network for hybrid fiber / coax structure of a variety of systems, the erbium-doped fiber amplifier is increasingly able to get attention, especially the front-end centralized system, point-to-multipoint light wave structure and long-distance trunk transmission system especially. For CATV designers most commonly tree distribution network, the efficiency of the system is determined by the cost per user. CATV amplifier is a electronic device that accept a varying input signal and produce an output signal that varies in the same way as the input, but has larger amplitude.Therefore, the use of erbium-doped fiber amplifier to increase the optical power on the basis of the original transmitting equipment, services for more users, thereby reducing the cost of the transmitter units of milliwatts. In addition, in recent years, including erbium-doped fiber amplifier 1550nm light emitting device can be the cheapest fiber to the curb and fiber to the building. All in all, CATV fiber trunk transmission and power distribution system as well as the progressive realization of the “triple play” of voice, video, data path transmission for the ultimate realization of broadband integrated services digital network, erbium-doped fiber amplifier will play an invaluable role.

For more Optical Amplifiers information,please visit fs.com or via Sales@fs.com to contact us.Fiberstore is profession supplier and manufacturer of optical amplifiers.You can save cost to buy fiber optic products by fiberstore.