Efficient and Fast All-Optical Modulator with In Situ Grown MoTe₂ Nanosheets on Silicon

All-optical modulators play a key role in building all-optical networks for efficient optical signal processing and have attracted intensive attention. In this paper, all-optical modulators with in situ grown molybdenum telluride (MoTe2) nanosheets on silicon are proposed and demonstrated for the first time with a self developed complementary-metal-oxide-semiconductor (CMOS)compatible fabrication processes. For the silicon-based all-optical modulators with a MoTe2-integrated microring resonator and microdisk resonator, the modulation is as efficient as 17.76 and 158.48 pm/mW while the rise/fall time is 3.7/3.6 and 1.5/3.3 its, respectively. This is the highest tuning efficiency and the fastest response speed among all-optical silicon modulators based on the photothermal effect of two-dimensional materials under the out-of plane pumping configuration. Furthermore, the manufacturing processes of the present devices are developed from in situ grown MoTe2 nanosheets on a silicon-on-insulator platform, which is CMOS-compatible, stable, and suitable for large-scale photonic integration.