High-Density and high-efficiency optical coupling packaging for 100 Gbps vertical cavity laser emitter array in CPO applications

The ever-increasing demands for computing power are beyond the capabilities of pluggable optical modules. Higher connectivity bandwidth can be achieved in a smaller volume with the Co-Packaged Optics (CPO) architecture. This study proposes a 90°-bent two-dimensional fiber array (2D-FA) for high-density optical coupling in CPO Applications. The optical coupling tolerances of 100 Gbps VCSEL was simulated. Simulation shows that 100 Gbps VCSEL requires ±17 μm transverse, 52 μm longitudinal and ±25° angular alignment at -1 dB loss. Moreover, the optical coupling tolerance of 100 Gbps VCSEL was tested in these three aspects: longitudinal, transverse, and angular. The optical coupling tolerance was also simulated. The possible errors during the experiment were used as simulation conditions. The trend of the simulation curve is basically consistent with the actual test curve. The results indicate that 2D-FA can achieve high optical coupling efficiency. This study proposes a high-precision assembly process based on temporary carriers. Its horizontal alignment error is less than ± 4 μm, and the vertical alignment error is less than 20 μm, enabling 3.2 Tbps optical engines.