7.1  DWDM:

  • DWDM (Dense wavelength – division multiplexing) is a data transmission technology having very large capacity and
  • Multiple data channels of optical signals are assigned different wavelengths, and are multiplexed onto one fiber.
  • DWDM system consist of transmitters, multiplexers, optical amplifer and Fig. 7.2.1 shows typical application of DWDM system.


  • DWDM used single mode fiber to carry multiple light waves of different frequencies.
  • DWDM systemuses Erbium – Doped Fiber Amplifers (EDFA) for its long haul applications, and to overcome the effects of dispersion and attenuation channel spacing of 100 GHz is used.