Coarse Wavelength-Division Multiplexing (CWDM) is a method of transmitting multiple signals over the same fiber optic cable by using different wavelengths of light. It is a type of multiplexing, which is a process of combining multiple signals into one transmission. CWDM utilizes the 1550 nm region of the optical fiber, also known as the C-Band. This allows multiple signals to be transmitted in the same fiber, with wide spacing between optical channels. The typical spacing between channels is several nanometers or more.
CWDM is primarily used to increase the existing capacity of a fiber optic cable. By sending multiple signals at different wavelengths, more data can be sent over the same cable. This is a cost-effective way of increasing the capacity of a fiber optic cable, as the cost of adding new single-mode fibers is much higher. Additionally, CWDM is used in fiber optic networks that require the transmission of multiple independent channels over the same fiber.
CWDM is a popular choice for fiber networks due to its low cost and scalability. It allows for the easy addition of new channels as the need arises, without the need to completely replace existing infrastructure. Additionally, CWDM allows for the intermixing of different data rate signals, making it possible to transmit both high-speed and low-speed data over the same fiber.
Overall, CWDM is an effective way of increasing the capacity of a fiber optic cable, while also making it possible to transmit multiple independent channels over the same fiber. It is a cost-effective solution for many fiber optic networks, and its scalability makes it a popular choice for many applications.