Numerical analysis and design of a new traveling-wave photodetector with an asymmetric i-layer cross section

We propose a new type of the traveling-wave photodetector (TWPD) that has an asymmetric intrinsic layer cross section to enhance bandwidth. In this paper, analysis and design of TWPDs are presented using the finite-difference time-domain method. A full-wave analysis is performed by a numerical technique and impulse responses are obtained in a linear regime. The simulation and experiment results show that 3-dB bandwidth is increased by the difference between electron and hole saturation velocities.