Communications can be broadly defined as the transfer of information from one point to another. In optical fiber communications, this transfer is achieved by using light as the information carrier. There has become an exponential growth in the deployment and capacity of optical fiber communication technologies and networks over the past twenty-five years.
Optical technology is the dominant carrier of global information. It is also central to the realisation of future networks that will have the capabilities demanded by society. These capabilities include virtually unlimited bandwidth to carry communication services of almost any kind, and full transparency that allows terminal upgrades in capacity and flexible routing of channels. Many of the advances in optical networks have been completed by the advent of the optical amplifier.
In general, optical amplifiers can be divided into two classes: optical fiber amplifiers and semiconductor amplifiers. The former has tended to dominate conventional system applications such as in-line amplification used to compensate for fiber losses. However, due to developments in optical semiconductor fabrication techniques and device design, especially over the last five years, the semiconductor optical amplifier (SOA) is showing great promise for use in evolving optical communication networks. It can be utilised as a typical gain unit but also has many functional applications including an optical switch, modulator and wavelength converter. These functions, where there is no conversion of optical signals into the electrical domain, are required in transparent optical networks.
Low-cost optical amplifiers
Cost reduction of optical amplifiers is of increasing concern because of continual pressure on the pricing of optical networking equipment, because of changes in applications and network architectures which are extending the range of applications of amplifiers beyond the line amplifier repeaters of the core network, and because the dominant EDFA technology is not as easily amenable to cost reduction through integration as other technologies such as semiconductors.
Low-cost optical amplifiers will be used in the highest volume, most cost sensitive applications, such as metro and access network line amplifiers, single-channel amplification for high speed, advanced modulation format channels, cable television distribution booster amplifiers(CATV) , and ASE sources for WDM passive optical networks (PONs). The complementary technologies for low-cost amplifiers, such as semiconductor optical amplifiers, and erbium-doped waveguide amplifiers (EDFA), (EDWAs) are covered. EDFAs, which is the dominant technology, comprises multiple components with different features and is based on different technologies.
The challenges and opportunities for reducing the costs of the primary components of EDFAs and the labor costs of assembling EDFAs are discussed, EDWAs offer opportunities for cost reduction by integrating the features of many of the components required for optical amplifiers. However, the lower efficiency of converting pump-to-signal power in erbium-doped planar waveguides compared with erbium-doped fiber, poses an obstacle to the commercial realization of the potential cost advantages of EDWAs, A recent approach is the PLC erbium-doped fiber amplifier, in which many of the passive devices are integrated on a PLC but the gain is provided by an erbium-doped fiber. This approach combines the advantages of PLC integration with the performance and pump efficiency of erbium-doped fiber and is especially advantageous for complex amplifier architectures requiring various optical components.
Fiberstore DWDM optical amplifier modules provide multi-function, low noise, Erbium-Doped Fiber Amplifier (EDFA) solutions that are ideal for metro Dense Wavelength Division Multiplexing (DWDM) applications. This family of C-Band 40 channels optical amplifiers is part of the fiber driver optical multi-service platform solution.
