Phosphorene‐assisted silicon photonic modulator with fast response time

Abstract All‐optical modulators avoid the conversion from external electronic signals to optical signals and thus have the potential to achieve an energy‐efficient high‐speed photonic system. Phosphorene recently debuted as an attractive material that exhibits outstanding high electron mobility, strong light‐matter interaction and modifiable bandgap, making it ideal for all‐optical modulators. In this paper, by incorporating a phosphorene and silicon‐based micro‐ring resonator (MRR), we first propose and experimentally demonstrate a unique phosphorene‐integrated all‐optical modulator in telecommunications. By utilizing a phosphorene thin film with an average thickness of 22 nm as the absorption material, the rise time of only 479 ns and decay time of 113 ns are achieved, which is the fastest reported response time in the family of phosphorene modulators. The corresponding 3 dB bandwidth is larger than 2.5 MHz, and it exhibits a low‐loss performance benefited from its finite bandgap. The proposed phosphorene/MRR hybrid modulator may have potential in the applications of all‐optical interconnections.