Comprehensive study on the nonlinear optical response of MoO2 nanosheets in pulsed lasers

Molybdenum dioxide nanosheets (MoO2-NSs), as two-dimensional (2D) materials, have attracted broad attention owing to their high damage threshold, good stability, strong localized surface plasmon resonance (LSPR), affordability, and excellent physicochemical properties. In this work, we successfully synthesized high-quality MoO2-NSs through chemical vapor deposition synthesis method and characterized the morphology and structure of the prepared materials in detail. The saturable absorption characteristics of the MoO2-NSs were measured using Z-scan experiments for the first time. Additionally, the compact Q-switched laser and stable mode-locked laser were successfully realized based on a MoO2-NSs saturable absorber (SA). To the best of our knowledge, this is the first presentation of the application of MoO2-NSs SA in the field of ultrafast photonics. These findings indicate that high-quality MoO2-NSs can be an effective optical modulator for generating high-repetition-rate pulsed lasers, and exhibit promising potential applications in mode-locked ultrafast lasers.