LR4 transceivers are designed for use with single-mode fiber (SMF). Single-mode fiber is optimized for longer-distance transmissions and typically has a narrower core, allowing signals to travel over greater distances without significant attenuation.
SR4 transceivers, on the other hand, are designed for use with multimode fiber (MMF). Multimode fiber is commonly used for shorter-distance connections within data centers.
LR4 modules are designed for long-range transmissions, typically supporting distances up to 10 kilometers (km) over single-mode fiber.
SR4 modules are optimized for short-range connections, typically supporting distances up to 100 meters (m) over multimode fiber.
LR4 modules use four separate wavelengths, commonly around 1295.56nm, 1300.05nm, 1304.58nm, and 1309.14nm. These wavelengths are multiplexed onto a single fiber for bidirectional communication.
SR4 modules use four separate wavelengths centered around 850nm. These wavelengths are typically used with parallel optics, where each wavelength corresponds to a separate optical lane.
Both LR4 and SR4 modules commonly use MPO/MTP connectors. However, it's important to note that the specific connector type might vary based on the manufacturer and product specifications.