Fang Yifei, Hao Jiajing, Sang Jianhua, Gao Jixing, Song Liwei, Tian Ye, Li Ruxin
State Key Laboratory of Ultra-intense Laser Science and Technology, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China.
Nat Commun. 2025 Jul 1;16(1):5598. doi: 10.1038/s41467-025-60851-w.
The coherent control of phonon polaritons (PhPs) in holds transformative potential for nonlinear photonics. We demonstrate terahertz-driven excitation of low-frequency PhPs in zinc oxide (ZnO) crystals, with their nonlinear dynamics resolved via time-resolved second harmonic generation (SHG) spectroscopy. By achieving phase matching via nine sequential reflections within a millimeter-scale crystal, we observe sustained SHG oscillations with 3-4 THz modulation frequencies, achieving optimal extinction ratios of ~18 dB that persist for 90 picoseconds-a temporal span directly governed by polariton propagation dynamics. This work establishes a dual-functionality platform enabling spectral-temporal resolved mapping of quasiparticle interaction dynamics while simultaneously advancing polariton-engineered nonlinear optical modulators through symmetry-broken frequency conversion architectures.
对声子极化激元（PhP）的相干控制在非线性光子学中具有变革潜力。我们展示了太赫兹驱动的氧化锌（ZnO）晶体中低频PhP的激发，其非线性动力学通过时间分辨二次谐波产生（SHG）光谱得以解析。通过在毫米级晶体中通过九次连续反射实现相位匹配，我们观察到具有3 - 4太赫兹调制频率的持续SHG振荡，实现了约18分贝的最佳消光比，该消光比持续90皮秒——这一时间跨度直接由极化激元传播动力学决定。这项工作建立了一个双功能平台，既能实现准粒子相互作用动力学的光谱 - 时间分辨映射，又能通过对称破缺频率转换架构推进极化激元工程化非线性光学调制器。
