Dense Wavelength Division Multiplexing Small Form-factor Pluggable (DWDM SFP) is the hot-pluggable transceiver used for Gigabit Ethernet which gathers different wavelengths together onto one single fiber. DWDM SFP has a more intensive wave spacing for a high performance of data communication, nowadays it can reach the speed up to 400Gbps on one optic fiber. The wave intervals are varied in 0.4nm, 0.8nm, 1.6nm etc. according to people’s need. The port of this transceiver still used the SFP interface for over 1 gigabit optical data transmission.