WDM is an acronym for wavelength division multiplexing, a technique that allows modulating different data streams of varying wavelengths onto a single optical fiber. Many consider WDM similar to FDM (frequency division multiplexing); however, they are different from each other. While WDM is carried out in the infrared (IR) portion of the electromagnetic spectrum, FDM takes place at radio frequencies (RF).
In WDM, each infrared channel transmits different radio frequency signals that are multiplexed through frequency division multiplexing or time-division multiplexing. Each multiplexed infrared channel is then demultiplexed and original signals are obtained at the destination. This way, it helps transmit data in different formats and at different speeds on a single fiber at the same time in each channel. As a result, you can enjoy enhanced network capacity while being cost-effective.
What is the purpose of using PM Filter WDM?
Polarization-maintaining filter wavelength division multiplexer, in short, PM Filter WDM, is the technology that helps maintain signal polarization while doing everything that a WDM device does, i.e. wavelength division multiplexing.
PM filter WDM helps facilitate bi-directional communication and boost signal capacity. As wavelength and frequency have related to each other inversely (the shorter the wavelength the higher the frequency), both use the same technology in them. On the receiving end, wavelength-sensitive filters are used.
In simple words, WDM systems can multiplex (combine) signals and then demultiplex (split) them at the final point. They are widely used by telecommunication companies and in various other applications because they allow engineers to expand the network capacity without laying more fibers.
Typically, WDM systems use single-mode (SM) optical fiber which carries only a single ray of light. However, other systems use multi-mode (MM) fiber cable.
Modern systems can handle up to 160 signals and can expand a basic 100 Gbps fiber system to a capacity of more than 16Tbps. You can find even a system of 320 channels. Hence, they find their exclusive application in optical fiber communication to send data in several channels with slight changes in wavelength. With WDM, you can increase the total bit rate of point-to-point systems while maintaining polarization. If we talk about PM Filter WDM specifically, they are mostly used to maintain polarized fiber amplifiers, DWDM networks, and instrumentation systems.
Apart from this, there are various benefits of using WDM technology. Some of these are:
- It multiplies the effective bandwidth and, thereby, increases the capacity of a fiber optic communication system.
- It reduces the overall cost and enhances the capacity of a cable that carries data.
- It has resulted in more efficient modern communication systems that can handle more challenges effectively.
While you can simply use a WDM for enhancing the capacity of a telecommunication network, you will need PM filter WDM when it comes to multiplexing polarized signals so that the polarization of signals remains maintained throughout the operation and network.