Compact 4 × 25 Gb/s optical receiver and transceiver for 100G Ethernet interface

We have developed the most compact 4 × 25 Gb/s ROSA (receiver optical sub-assembly) module and the most compact optical transceiver module for 100G Ethernet optical interface over up to 10km single mode fiber. They are compliant with CFP4 MSA and IEEE 802.3ba 100GBASE-LR4 standard. In order to reduce the size and simplify the manufacturing process of the 4 × 25 Gb/s ROSA module, we propose a butt-coupling structure between an optical demultiplexer and four PD chips. The optical transceiver has eye margins of more than 20%, and the receiver sensitivities of less than -11.5 dBm for four channels.