CWDM4 Optical Module

CWDM4 is a 100G optical transceiver standard that uses four 25 Gbps lanes over duplex single-mode fiber for cost-effective, medium-distance Ethernet connections up to 2 km.Key Features and SpecificationsCWDM4 modules operate using Coarse Wavelength Division Multiplexing (CWDM), combining four distinct 25 Gbps optical lanes onto two strands of single-mode fiber—one for transmit and one for receive—achieving 100 Gbps aggregate bandwidth . The four wavelengths are typically 1271 nm, 1291 nm, 1311 nm, and 1331 nm, spaced 20 nm apart . Each lane runs at 25.78 Gbps, and the modules are designed for duplex LC optical connectors, though connector types may vary by vendor . CWDM4 modules comply with the 100G CWDM4 MSA and are compatible with QSFP28 and CFP4 form factors, supporting interoperability across multiple vendors . The modules require forward error correction (FEC) implemented by the host system to maintain reliable operation and meet IEEE 100G standards .Performance and ReachThese modules are optimized for medium-distance links, typically up to 2 kilometers over single-mode fiber without repeaters . They are ideal for data center interconnects (DCI), enterprise backbone networks, and metro or service provider networks where cost-effective 100G connectivity is needed . Unlike 100G LR4 modules, CWDM4 uses different wavelengths, making CWDM4 and LR4 interfaces incompatible .AdvantagesEfficient fiber usage: Only two fibers are needed for 100G, reducing cabling complexity compared to parallel optics solutions like SR4 or PSM4 .Cost-effective: Lower cost than LR4 modules due to simpler optics and reduced fiber requirements.Interoperability: Multi-vendor support ensures seamless deployment in existing networks .Compact form factor: QSFP28 modules are small and suitable for high-density switch ports .ApplicationsData Center Interconnects (DCI): Connecting servers, top-of-rack switches, and aggregation switches within or between data centers.Enterprise Networks: High-speed links between core switches and routers.Telecom & Service Providers: Metro access and edge applications requiring 100G client interfaces.Storage and Virtualization: Supporting high-bandwidth SANs and network function virtualization (NFV) deployments . CWDM4 modules provide a reliable, scalable, and cost-efficient solution for 100G Ethernet links over medium distances, making them a cornerstone technology for modern high-speed networks .