1.9 Tbps receiver optical subassembly based on LAN-WDM hybrid integration

A low-cost, hybrid-integrated 1.6-TbE local-area network wavelength-division multiplexing (LAN-WDM) receiver optical subassembly (ROSA) based on an O-band arrayed waveguide grating (AWG) demultiplexer has been developed. Vertical coupling between the AWG and the photodetector (PD) array is achieved by polishing the AWG output facet at an angle of 41°, resulting in a maximum coupling efficiency of 88.4%. A flexible printed circuit (FPC) board with 16 differential high-frequency coplanar waveguides (CPWs) is designed to deliver radio-frequency (RF) signal outputs and to supply power to the transimpedance amplifier (TIA) and PD arrays. All lanes of the ROSA exhibit receiver sensitivities better than -7.3 dBm and support the transmission of a single-channel 60-GBaud four-level pulse-amplitude modulation (PAM-4) signal, enabling an aggregate data rate of 1.9 Tb/s.