Modeling and Characterization of Photovaractor for Microwave Optoelectronics

Optical control of microwave circuits using photodiode junction capacitance variation due to optical illumination has some advantages such as simplicity and wide possibilities in application, high tuning range, accuracy, and speed. We have proposed to call as photovaractor the device which capacitance changes under illumination and which is used for optical control of microwave circuits. The numerical one-dimensional drift-diffusion model of the photovaractor based on the InP/InGaAs/InGaAsP heterostructure which is taking into account influence of the external electric circuit and parasitic elements was used to calculate the junction capacitance change under illumination. The experimental results and theoretical study of the photovaractor in the frequency range up to 3 GHz are presented.