Effects of input optical power in lateral Ge-on-Si waveguide photodetectors: a 3D multiphysics modeling study

We present a three-dimensional (3D) multiphysics model that examines how increasing input optical power degrades the electro-optical frequency response performance of lateral Ge-on-Si waveguide photodetectors. Our approach combines finite-difference time-domain (FDTD) simulations and drift-diffusion modeling to capture both optical and electrical behaviors. Simulation results show that once the input power exceeds a few mW, the detector bandwidth is significantly reduced due to electric-field screening effects.