Hi Ranjeet.
as far as DWDM is concerned , Dense Wavelength Division Multiplexing (DWDM) is a technology that allows multiple information streams to be transmitted simultaneously over a single fiber. This provides a cost effective method to increase the capacity of the existing networks without the need to add additional fiber. This application note explains capabilities of the OptiSystem software to explore different design structures (e.g. modulation format, linear and nonlinear impairment compensation) to optimize the performance of these networks for access and long-haul application.
It has few applications:
Long-haul optical networks either in point-to-point or ring topology, Expanding the capacity of an existing optical network and Capacity leasing for network wholesalers.
Hope it helps
Regards