The demultiplexer separates the multiple of wavelengths in a fiber and directs them to many fibers.įigure 1: Components of a Traditional OADM
Then the reconfiguration can be achieved by a fiber patch panel or by optical switches that direct the wavelengths to the optical multiplexer or to drop ports.
The multiplexer is used to couple two or more wavelengths into the same fiber. This makes it possible for OADM to remove or insert individual wavelengths.Īn OADM generally consists of three parts: an optical demultiplexer, an optical multiplexer, a method of reconfiguring the paths between the optical demultiplexer and the optical multiplexer, as well as a set of ports for adding and dropping signals. If a demultiplexer is placed and properly aligned back-to-back with a multiplexer, it is clear that in the area between them, two individual wavelengths exist. We know that the main function of an optical multiplexer is to couple two or more wavelengths into the same fiber. Since the OADM is based on low-loss, low-cost passive devices and does not need any power supply, a reliable, cost-effective and scalable network can be achieved with its help.Īs a key component for DWDM and UW-WDM (ultra wide wavelength division multiplexing) optical networks, OADM is used for selectively dropping and inserting optical signals into a transparent DWDM network. To fulfill this requirement, optical add-drop multiplexers (OADMs) were introduced in metro/access networks, serving as the simplest elements to introduce wavelength management capabilities by enabling the selective add and drop of optical channels. The enormous growth in the demand for bandwidth is pushing the utilization of fiber infrastructures to their limits.