WDM technology

WDM technology currently used widely for ultra long distances and high capacity

Capacities more than Tera bits per second can be reached

Distances more than 5000 km can be reached

WDM has 2 types: CWDM and DWDM

WDM use laser source

DWDM used for long distances and high capacity but CWDM can be used with up to 8 channels

DWDM use single mode optical fiber

ITU has Many standards for optical cables, g652 and g655 is the most common fiber cables used with DWDM

We use c band
C band is from 1525 - 1565 nm and from 191 to 196 Tera Hertz