Fabrication of Butt-coupling-capable Optical Receiver Assemblies for Optical Interconnections

Recently, optical interconnections have been considered a promising solution for transmitting at extremely high data rates and for transmitting a large number of data channels in intra-board and inter-board communications. We have fabricated two types of butt-coupling-capable optical receiver assemblies for optical interconnections. An organic FR4 printed circuit board (PCB) has been used as a substrate for integrating a photodiode (PD) device with an electrical receiver IC chip. A bottom-absorption PD and an interposer PCB with a top-absorption PD have been developed to implement a sidewall attachment on an organic substrate of the PD device for a butt-coupling capability. The optical receivers have been characterized by connecting the optical transmitter to a multimode fiber probe. Further, their operations have been demonstrated over 5-Gbps.