High-speed uni-traveling-carrier photodetector with the new design of absorber and collector

High-speed uni-traveling-carrier photodetector (UTC-PD) and three modified uni-traveling-carrier photo-detectors (MUTC-PDs) incorporating different doping profile are designed and simulated for a wavelength of 1550 nm in this letter. According to comparison of simulated results, UTC-PD-1, MUTC-PD-2 and MUTC-PD-3 with constant doping profile, step-constant doping profile and Gaussian doping profile in InGaAs absorber are respectively achieved the 3-dB bandwidth of 45.8 GHz, 48.2 GHz and 178.9 GHz, while the MUTC-PD-4 incorporating Gaussian doping profile in InGaAs absorber and InP collector is obtained the 3-dB bandwidth of up to 182.9 GHz under the same reverse bias voltage of 1.5 V. Afterwards, the high-speed response characteristics of different area are simulated and achieved the 3-dB bandwidth of 26 GHz, 55 GHz, 118 GHz and 182.9 GHz at the area of 100 μm², 40μm², 20 μm² and 14 μm².