High-performance inverted evanescently coupled waveguide integrated MUTC-PD with high response speed

Here we propose an inverted evanescently-coupled waveguide modified uni-traveling-carrier photodiode (IECWG MUTC-PD) and verify the character numerically. In this photodiode, the epitaxial structure is inverted from p-i-n to n-i-p, and a diluted waveguide is applied. The material of capacitance control layer is optimized to realize energy band compensation and capacitance control. Such structure possesses a large electric field in the whole depletion region and has a uniform light absorption, which improves the space charge effect. As a result, the PD achieves a 3-dB bandwidth of 71.9 GHz with a 35µm2 active area at -5V bias voltage and an internal responsivity of 0.59 A/W in 7-µm long short PD with a 200-nm-thick absorption layer.