{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"omics_type":["Unknown"],"volume":["12(13)"],"submitter":["Cai J"],"pubmed_abstract":["Strong-field terahertz (THz)-matter interaction permits the investigation of nonequilibrium behaviors in the nonperturbative zone. However, the unavailability of a high-field free-space THz source with high repetition rates, excellent beam quality, and high stability hinders its development. In this work, we obtain the nonlinear modulation dynamics of a \"THz-nano\" metasurface on silicon substrates using a time-resolved strong-field THz-pump THz-probe (TPTP) with a thousand orders local field enhancement through confining THz waves into nano-gaps (15 nm, <i>λ</i>/33,000). By switching the THz field strength, we successfully realize a self-modulation ∼50 GHz frequency shift, which is further verified via the TPTP ultrafast time-resolution technique. The phenomenon is attributed to the impact ionization (IMI) of the silicon substrate under the excitation of extremely confined strong THz fields in nano-gaps. Both strong-field induced intervalley scattering (IVS) and IMI effects of photodoped silicon occurring in nano-gaps and large-area substrates were also observed by 800 nm optical injection of carriers. These aforementioned findings provide a robust research platform for the realization of ultrafast time resolution nanoscale strong-field THz-matter interaction and new ideas for nonextreme laboratories to realize extreme THz science, applications, and THz nonlinear modulation device development."],"journal":["Nanophotonics (Berlin, Germany)"],"pagination":["2517-2526"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC11501971"],"repository":["biostudies-literature"],"pubmed_title":["Ultrafast strong-field terahertz nonlinear nanometasurfaces."],"pmcid":["PMC11501971"],"pubmed_authors":["Geng C","Li J","Quan B","Cai J","Chen S","Wu X"],"additional_accession":[]},"is_claimable":false,"name":"Ultrafast strong-field terahertz nonlinear nanometasurfaces.","description":"Strong-field terahertz (THz)-matter interaction permits the investigation of nonequilibrium behaviors in the nonperturbative zone. However, the unavailability of a high-field free-space THz source with high repetition rates, excellent beam quality, and high stability hinders its development. In this work, we obtain the nonlinear modulation dynamics of a \"THz-nano\" metasurface on silicon substrates using a time-resolved strong-field THz-pump THz-probe (TPTP) with a thousand orders local field enhancement through confining THz waves into nano-gaps (15 nm, <i>λ</i>/33,000). By switching the THz field strength, we successfully realize a self-modulation ∼50 GHz frequency shift, which is further verified via the TPTP ultrafast time-resolution technique. The phenomenon is attributed to the impact ionization (IMI) of the silicon substrate under the excitation of extremely confined strong THz fields in nano-gaps. Both strong-field induced intervalley scattering (IVS) and IMI effects of photodoped silicon occurring in nano-gaps and large-area substrates were also observed by 800 nm optical injection of carriers. These aforementioned findings provide a robust research platform for the realization of ultrafast time resolution nanoscale strong-field THz-matter interaction and new ideas for nonextreme laboratories to realize extreme THz science, applications, and THz nonlinear modulation device development.","dates":{"release":"2023-01-01T00:00:00Z","publication":"2023 Jun","modification":"2025-04-18T22:39:31.646Z","creation":"2025-04-07T10:23:01.368Z"},"accession":"S-EPMC11501971","cross_references":{"pubmed":["39633754"],"doi":["10.1515/nanoph-2022-0766"]}}