In this paper, the latest theoretical model of superluminescent diode is established based on the effect of energy level divergence. The theoretical simulation results agree well with the experimental results.

The performance of a low-bias cascade uni-traveling carrier photodiode (UTC-PD) array was studied. Compared with the single UTC-PD, the cascade UTC-PD array can increase the 3-dB bandwidth by 47.5% and has better DC saturation performance. © 2020 The Author(s).

In this paper, the performance of uni-traveling carrier photodetector is investigated operating back, front and double light illuminating ways. The simulation results show that the back illuminated device shows the best performance. And the 3-dB bandwidth and responsivity are 26 GHz and 0.179 A/W, respectively. The front illuminated device shows the highest saturation characteristics, reaching to 1.9e5 W/cm2. The active layer radius of device is 14 μm and reverse bias is 0.1 V. In addition, the reasons account for the performance difference can be summed up as the following three points:Absorption of light by p-contact layer, the reflection of anode and the differences of electric field profile in the absorption layer.