Dense Wavelength Division Multiplexing (DWDM) is a more expensive solution with much higher bandwidth and distance capabilities. It is utilised in long-haul networks, submarine cable systems and applications where very high data transmission rates are required.
DWDM modules commonly operate in the C-Band wavelength range which is approximately 1530nm – 1565nm with some also utilising the adjacent L-Band range (1565nm – 1625). They have much smaller wavelength spans between channels allowing for 40+, and therefore huge bandwidth capacities. The tighter channel spacing allows for more precise control over each wavelength which is a key factor in the suitability for long range communications. DWDM modules use cooling systems to maintain the accuracy of the lasers which need to stay precise due to the small channel spacing. This makes them more complex, power intensive and subsequently more expensive.
DWDM systems are suited to reach hundreds, or even thousands of kilometers (with the help of amplifiers). The C-Band and L-Band wavelength ranges in which DWDM modules operate generally have comparatively low attenuation to other ranges like the 1270nm – 1610nm in which CWDM operates. This, along with various dispersion compensating techniques and amplification work to keep DWDM signals accurate over significantly longer distances than CWDM, making them suitable for very far and data intensive communications.
See our Tech Talk post for more information on Wavelength Division Multiplexing (WDM) and how it works. You can find our DWDM Wavelength and Channel guide here.
