A 226.875-Gbit/s/λ Optical Receiver Based on a High-Frequency Integration by Flip-Chip Mounting

A high-speed optical receiver for IM-DD 226.875-Gbit/s/ $\lambda $ transmission was designed and fabricated by using high-frequency, integrated flip-chip (FC) mounting. Thanks to the developed FC-mounting technique, the optical receiver exhibited high 3-dB bandwidth and less-fluctuation optical-to-electrical (O/E) frequency response. The fabricated optical receiver demonstrated 3-dB bandwidth of 55.1 GHz with less-fluctuation O/E frequency response up to 50 GHz (i.e., Nyquist frequency under 100-Gbaud operation at 4-PAM modulation frequency). The simulated transmission performance of the optical receiver reveals that its link budget for 226.875-Gbit/s/ $\lambda $ transmission is expanded by 3.7 dB by using the developed FC-mounting technique. The fabricated optical receiver also experimentally demonstrated transmission of a 226.875-Gbit/s signal over 20-km SSMF.