14 March 2018

What is DWDM

Before we learn about the DWDM first let it check out the full form of DWDM. DWDM stands for dense wavelength division multiplexing. Hence the dense means the wavelength channel is very narrow and also very close to each other. 

Dense wavelength division multiplexing(DWDM) is technology put data from different sources together in an optical fiber, which uses single-mode fiber to carry multiple light waves of different frequencies.

For 100 GHz dense WDM, the interval between the adjacent channel is only 100 GHz, for example, the adjacent channels could be 1533.33 nm, 1533,12 nm, 1531.90 nm.

DWDM is widely used for the 1550 nm band so as to help the capabilities of EDFA full formEDFA as are commonly used for the 1525 nm - 1565 nm.

Dense wavelength division multiplexing is an important innovation in optical network and provides many benefits of DWDM. It can be used various applications like  u
tilize the existing thin fiber and building or expanding a network

DWDM system structure :

DWDM system consists of transmitter, receiver, Multiplexer, optical amplifier (EDFA), demultiplexer. The figure shows a typical application of a DWDM system

Transmitter: Laser that transmits data with a very accurate wavelength each laser is configured to transmit in a certain wavelength.

Receiver: Component that receives the signal and transmits them into a de-multiplexer.

DWDM system
EDFA: Erbium-doped fiber amplifier. Optical repeater device that amplifies the optical signal, It is a silica-based optical fiber that doped with erbium that boosts the power of the wavelength.

Add and drop: Component that receives a fiber optic with some wavelength multiplexed, and can drop or add a certain lambda from the signal.

DWDM multiplexers: Receive many optical signals, each one is a different wavelength, and transmit the entire wavelength in one optic fiber.

DWDM de-multiplexer: Receive all the signal in one optic fiber, and transmit each wavelength in a different fiber.

DWDM applications:
  • It can be used for signal transmission
  • It is ready to make for long distance, Telecommunication operator that use either point to point or ring topology 
  • Utilize the existing thin fiber
  • Building or expanding network
  • The transparency of the DWDM system to  various bit-rate and protocols
  • Network wholesalers can lease capacity rather than entire fiber cable