Design of a resonant-cavity-enhanced photodetector for high-speed applications

We present a theoretical study of the effects of light field distribution on the frequency response of a resonant-cavity-enhanced p-i-n photodetector. Taking advantage of the flexibility of cavity design, one can tailor the light field distribution in the absorption region. Because of the difference in velocities of the carriers, the speed performances of the detector depend on the field distribution and the cavity design. The results of our work indicate that when the maximum of light field intensity happens near the p⁺ edge of the depletion layer, the device shows the best speed performance. The frequency response, the impulse response, and the step response have been calculated for different structures to demonstrate the importance of the field distribution