High-Power Silicon-Doped Waveguide PIN Photodetectors with Lateral Si/Ge/Si Heterojunctions

This study proposes a high-power optical waveguide p-i-n photodetector (PD) based on a lateral Si/Ge/Si structure with all-silicon doping designed for operation in the 1550 nm wavelength band. A parallel dual PD, featuring a shared signal (s-pole) electrode, forms an equivalent parallel resistance, maintaining bandwidth despite the doubling of junction capacitance. The double-sided illumination ensures a uniform optical field distribution, enhancing thermal tolerance. Parameter extraction was performed using the least squares fitting method. The proposed photodetector (PD) achieves a maximum photocurrent of 30.7 mA with a high responsivity of 0.81 A/W and is capable of handling optical powers exceeding 200 mW. It exhibits a broad bandwidth of 54 GHz under low optical power and maintains over 28 GHz bandwidth at an input power of 15 dBm. Moreover, clear 30 Gb/s eye diagrams are observed under an incident optical power of 17 dBm.