Design and Optimization of a Photodetector Electrode Incorporating a High-Impedance Transmission Line Structure

Optical communication systems increasingly demand photodetectors with broader bandwidth and lower losses. The performance of a photodetector is critically influenced by its electrode design. This paper presents a novel low-loss photodetector electrode structure that optimizes frequency response by incorporating a high-impedance transmission line. After optimization, the electrode's characteristic impedance approaches 50 ohms, the bandwidth reaches 258GHz, an increase of 42.3%, and the loss at 200GHz is -1.69dB.