摘要
Achieving efficient and intense second-harmonic generation(SHG)in the terahertz(THz)spectrum holds great potential for a wide range of technical applications,including THz nonlinear functional devices,wireless communications,and data processing and storage.However,the current research on THz harmonic emission primarily focuses on inorganic materials,which often offers challenges in achieving both efficient and broadband SHG.Herein,the remarkable efficiency of organic materials in producing THz harmonics is studied and demonstrated,thereby opening up a new avenue for searching candidates for frequency-doubling devices in the THz band.By utilizing DAST,DSTMS,and OH1 crystals,we showcase their superior frequency conversion capabilities when pumped by the narrowband THz pulses centered at 2.4,1.6,and 0.8 THz.The SHG spans a high-frequency THz domain of 4.8 THz,achieving an unprecedented conversion efficiency of∼1.21%while maintaining a perturbative nonlinear response.The highly efficient SHG of these materials is theoretically analyzed by considering the combined effects of dispersion,phonon absorption,polarization,and the nonlinear susceptibility of organic crystals.This work presents a promising platform for efficient THz frequency conversion and generation across a wide range of frequencies,offering new opportunities for novel nonlinear THz applications in next-generation electronics and optics.
基金
supported by the National Key R&D Program of China(Grant No.2022YFB3806000)
the National Natural Science Foundation of China(Grant Nos.61935001,62205020,62205294,52332006,92163129,and U2241226)
the China Postdoctoral Science Foundation(Grants Nos.2022M710372 and 2022M710130)
the Zhejiang Science and Technology Association young talent lifting project
the Beijing Science and Technology Association young talent lifting project.
