The most common encapsulations for 100Mbps and 1Gbps optical modules are SFP. For 10Gbps modules, the encapsulation is usually SFP+, while for 25Gbps/40Gbps/100Gbps/400Gbps, the encapsulations are SFP28/QSFP/QSFP28/QSFP-DD respectively. They comply with the specifications defined in the multi-source agreement (MSA) and support synchronous optical. These modules convert electrical signals to optical signals and vice versa, ensuring seamless communication between devices. By wavelength: conventional wavelength, CWDM, DWDM, etc. By mode: single-mode fiber (yellow), multi-mode fiber (orange-red). By Usability:. Optical modules are encapsulated in different modes to provide different structures. SFP: small form-factor pluggable.