Engineering silicon waveguide nonlinear loss for integrated microwave photonics links

As a fundamental components for the integrated microwave photonic links, the nonlinear loss of the Silicon waveguides will significantly affect the links’ performance. We study the effects of the effective mode area (Aeff), two-photon absorption (TPA), free-carriers absorption (FCA), and linear propagation loss on the insertion loss in silicon waveguides. According to our simulations, the results show that it should be an efficient way to reduce the insertion loss of the silicon by combining the large mode area, small linear propagation loss and carriers sweep out techniques. And, we can also know that when the nonlinear loss will dominate with the coupled power becoming larger. Thus, the results can provide guidances on the gain, loss, and linear dynamic range of analog photonics links based on silicon waveguide.