Effects of Gamma and Proton Irradiation on 100 Gbps Silicon Modulators

Abstract

We investigated the impact of γ-rays and proton irradiation on the performance of high-speed modulators by exposing four-channel 4 × 100 Gbps silicon transmitter chips to both of these radiation sources. The results of our studies indicate that the modulators demonstrated exceptional radiation resistance for various combinations of energy-dose exposure to γ-rays and proton irradiation in terms of the electro-optic modulation rate, extinction ratio, and modulation efficiency. When subjected to a cumulative radiation dose of 25 Mrad(Si) γ-rays irradiation, the modulation bandwidth decreases from 52 to 31 GHz. Nevertheless, it was mostly restored using a 7 h annealing procedure at a temperature of 100 °C. Proton irradiation at different energy levels and fluences did not have significant detrimental effects on the performance of the modulators. Moreover, it did enhance the modulation efficiency at low fluence.