Design and fabrication of a small‐form transmitter optical subassembly for 100 Gbps short reach optical interconnect

Abstract

AbstractA high‐coupling‐efficiency and convenient‐integration transmitter optical subassembly for 25 Gbps small‐form transceiver is developed in this paper. In the structure, the VCSEL is vertically mounted on the silicon substrate by the flip‐chip method to enable direct and passive alignment with the fibers plugging in the fiber guide holes on the silicon substrate. By the optical simulation, the maximum coupling efficiency of VCSEL is −0.38 dB. The vertical electrical pads of the VCSEL are connected to the horizontal wire‐bonding pads on silicon substrate by the 90°‐bend GS micro strip lines. Thus, the interconnection between the transmitter optical subassembly and the electrical PCB board is conveniently realized by the low‐cost wire‐bonding method. The electrical performance of the 90°‐bend GS micro strip lines on the optical subassembly is also evaluated by the 3D electromagnetic simulation. In order to verify the transmission performance of the transmitter optical subassembly, it is integrated with an electrical board using bonding wires, and then the optical performance of the transmitter is measured. By the measurement, the optical subassembly can operate up to 25 Gbps per channel.