An ultra-compact 25-Gbit/s × 4-ch active optical cable with gapped ground electrode structure

A 25.78-Gbit/s × 4-ch active optical cable (AOC) with a ultra-compact form factor is proposed. The size of the proposed AOC is 5.2 cm
³
, which is 45-% smaller than the standard form factor of a pQSFP. By utilizing a gapped ground electrode structure, the proposed AOC demonstrated 25.78-Gbit/s error-free optical transmission under all-channels (4-ch) operation, and improved bit error rate (BER) power penalty of about 1.8 dB compared with a conventional ground structure.