The 100G-DR-LPO specification by the LPO (Linear Pluggable Optics) MSA defines 100 Gb/s/lane 53. 125 GBd PAM4 optical interfaces, optical links using standard single-mode fiber with up to 500 m reach, and host-module electrical interfaces for hosts with DSP based SerDes and RS(544,514) FEC. 1 shows the typical block diagram of a pluggable transceiver consisting of on-board lasers, optics, a Photonics die housing the modulator. Linear Drive Pluggable Optics refers to the use of direct-drive linear technology in fiber modules. According to the LPO MSA, an LPO solution offers power savings for optical interconnect by removing the digital signal processing (DSP) function from the pluggable optical module. The idea is simple: instead of a DSP (digital signal processor) inside the module – replacing it with transimpedance amplifier (TIA) and a driver chip with high linearity and EQ capability – LPO shifts signal processing into.
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