Modern-day applications like 5G, AI, ML, and HPC have dramatically increased the volume of traffic through datacenters. Conventional pluggable optics cannot keep up with the growing need for high bandwidth and low power density. Co-packaged optics (CPO) can provide the solution by bringing the optics closer to the electronics and by dramatically reducing the length of the electrical links. However, there are unique Multiphysics and multi-scale design challenges that need to be overcome. Firstly, there is the challenge of efficiently coupling the optical signal in and out of the photonic IC (PIC). The photonic coupler needs to be designed while accounting for the alignment and angle of the fiber. Designers also must ensure that the fiber alignment holds in the package via some passive or active alignment techniques. Next comes the thermal design challenge. By placing the PIC inside the electrical package, we increase the possibility of thermal crosstalk. While the thermal power from heaters and laser sources in the photonic die will affect the temperature map of the package, the heat generated in the electrical dies and the cooling mechanism of the overall system will affect the thermal behavior of the PIC. A complete thermal analysis from die to system level is therefore needed. Finally, the designer needs to perform a transient simulation of the entire system to ensure signal and power integrity. This will require self-consistent electrical and photonic circuit simulations while accounting for the additional parasitic effects coming from the different types of electrical interconnects introduced at the packaging stage. This presentation will show how we are utilizing the Multiphysics portfolio of Ansys to address these design challenges and establish a comprehensive design solution for CPO.
Dr. Ahsan Alam is a Lead R&D Engineer at Ansys. His areas of expertise include simulation and modeling of solid state electronic and photonic devices and circuits. As the lead for photonic foundry engagements, he collaborates with foundry partners on various projects ranging from PDK development to photonic ecosystem development. He is also involved in the development of Ansys Lumerical’s system suite and plays the role of a product manager.