Multiwavelength Light-Driven Broadband Terahertz Modulation Based on Manganese Oxide Nanoparticles

In the era of artificial intelligence-driven information explosion, hybrid terahertz (THz) optical systems can play a pivotal role in multiple dimensional information transmission, which relies on high-performance THz modulators capable of multiwavelength optical excitation. Here, we present a multiwavelength light-driven broadband THz modulator based on manganese oxide nanoparticles (MnO NPs), exhibiting excellent broadband modulation within the frequency range of 0.1–1.6 THz and large modulation depth under different wavelength laser illumination at proper powers. The experimental results demonstrate that the THz modulator based on MnO NPs possesses superior compatibility and applicability compared with the traditional THz modulators. Based on the forward light scattering enhancement effect of the nanoparticles, the MnO NPs can effectively achieve light absorption enhancement at the interface between the nanoparticles and the silicon substrate, thereby significantly increasing the surface photoconductivity at the interface under optical excitation. Furthermore, the experimental results were effectively evaluated through numerical simulations within the framework of Drude model. Our work provides a compact and efficient solution for developing high-performance broadband THz modulators with large modulation depth and multiwavelength optical excitation, demonstrating the great potentials for advancing the next generation hybrid integrated THz optical systems.