What is the difference betweenCWDM and DWDM?

Both use the same technological concepts of optical multiplexing.
The only difference is in the number of lambdas(wavelengths) that are used in DWDM and the separation between them.
In CWDM, lambda separation is 20nm, in DWDM this separation varies between 0.8nm and 1.6nm, depending on the operating band.
This requires the DWDM laser to be stable, and to maintain this precision, it has to operate within a particular range of temperatures so that the transmission frequency does not vary.

Some of the services that can be provided using dwdm


MetroSAE TELNET 8 Lambdas CWDM Multiplexer	CWDM Multiplexer integrate up to 8 channels of information on a single pair of optical fiber. The wavelengths from 1270nm to 1610nm separated by 20 nm.		Telnet-RI CWDM Multiplexer works in wavelengths in bands S, C and L (1470nm to 1610nm).

16 Lambdas 200GHz DWDM Multiplexer

DWDM Multiplexer module of TELNET allows to integrate up to 16 channels of information on a single pair of optical fiber.

Gigabit Ethernet

10GbE

SDH in STM-1, STM-4, STM-16, and STM-64 hierarchies,

FiberChannel 1G, 2G, 4G, and 10G

ESCON

FICON

Online Telecom Exhibition