The 100G QSFP28 ER4 optical transceiver transmits data over single mode fibre at a distance of up to 40km. The transceiver operates on 4 wavelengths and works in point-to-point scenario. LAN-WDM optics transmit the 100 Gigabit Ethernet (100G) signal over duplex single-mode fibers multiplexing/demultiplexing four 25G wavelengths within the transceiver. The module converts 8 channels of 50Gb/s (PAM4) electrical input data to 4 channels of LAN WDM optical signals and multiplexes them into Char nd not the principal indicator of signal strength. The "ER" in its name stands for "Extended Range," clearly indicating its core advantage: the ability to transmit over single-mode fiber for distances. QSFP 40G ER4 is a long-reach 40Gbps optical transceiver designed for up to 40km transmission over single-mode fiber, making it a practical choice for data center interconnection, metro links, and enterprise backbone networks that exceed the 10km range of standard 40G optics.
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