A universal route to efficient non-linear response via Thomson scattering in linear solids
Yongzheng Wen, F. Giorgianni, Igor Ilyakov, Baogang Quan, Sergey Kovalev, Chen Wang, C. Vicario, Jan‐Christoph Deinert, Xiaoyu Xiong, Joe Bailey, Min Chen, Alexey Ponomaryov, Nilesh Awari, Andrea Rovere, Jingbo Sun, Roberto Morandotti, Luca Razzari, G. Aeppli, Junjie Li, Ji Zhou
Abstract
Non-linear materials are cornerstones of modern optics and electronics. Strong dependence on the intrinsic properties of particular materials, however, inhibits the at-will extension of demanding non-linear effects, especially those second-order ones, to widely adopted centrosymmetric materials (for example, silicon) and technologically important burgeoning spectral domains (for example, terahertz frequencies). Here we introduce a universal route to efficient non-linear responses enabled by exciting non-linear Thomson scattering, a fundamental process in electrodynamics that was known to occur only in relativistic electrons in metamaterial composed of linear materials. Such a mechanism modulates the trajectory of charges, either intrinsically or extrinsically provided in solids, at twice the driving frequency, allowing second-harmonic generation at terahertz frequencies on crystalline silicon with extremely large non-linear susceptibility in our proof-of-concept experiments. By offering a substantially material- and frequency-independent platform, our approach opens new possibilities in the fields of on-demand non-linear optics, terahertz sources, strong field light-solid interactions and integrated photonic circuits.