Application of the TLM method for the characterization of traveling wave photodetectors

The time-domain TLM method was used for the rigorous analysis of traveling wave photodiodes. The calculation of bandwidth included effects like velocity mismatch, finite saturation velocity of the photogenerated carriers and RF and optical attenuation constant. The obtained data were compared with experiments and data obtained by other numerical techniques. An excellent agreement was observed with FDTD results, while comparing to the equivalent circuit data, our results were in much better agreement with experiment. The effects of the optical attenuation coefficient on the photodetector's bandwidth were investigated as well.