Does the 40ge model have a single-mode optical module

Yes, the 40GE model supports single-mode optical modules for long-distance transmission.

Single-Mode Module Availability

40GE QSFP modules are available in single-mode versions designed for long-distance fiber connections. For example, the Huawei QSFP-40G-LX4 is a single-mode module operating at 1310 nm with a reach of up to 2 km over single-mode fiber using LC connectors . Additionally, DWDM 40G QSFP modules support distances up to 80 km over standard G.652 single-mode fiber, with ITU-T DWDM grid compliance and digital diagnostics via I2C interface .

Single-Mode vs Multimode

• Single-mode modules are used with single-mode fibers, which support long-distance transmission and higher bandwidth, making them suitable for data center interconnects and metro networks .
• Multimode modules are used with multimode fibers, optimized for short-distance links (typically up to a few hundred meters) and lower cost, but with lower transmission performance due to modal dispersion .

Key Features of 40GE Single-Mode Modules

• Wavelengths: Commonly 1310 nm for LX4 modules; DWDM modules use ITU-T defined wavelengths.
• Connector Type: LC duplex for LX4; DWDM modules may use standard single-mode fiber connectors.
• Distance: LX4 up to 2 km; DWDM modules up to 80 km with optional EDFA and dispersion compensation modules for longer links.
• Compliance: Laser Class 1, QSFP+ MSA SFF-8636, and IEEE 802.3ba standards . In summary, if your 40GE switch requires long-distance single-mode connectivity, you can use modules like QSFP-40G-LX4 or DWDM QSFP, depending on the required distance and network design. These modules are fully compatible with standard single-mode fibers and provide reliable high-speed 40G links.