摘要
Optical cavities play crucial roles in enhanced light-matter interaction,light control,and optical communications,but their dimensions are limited by the material property and operating wavelength.Ultrathin planar cavities are urgently in demand for large-area and integrated optical devices.However,extremely reducing the planar cavity dimension is a critical challenge,especially at telecommunication wavelengths.Herein,we demonstrate a type of ultrathin cavities based on large-area grown Bi_(2)Te_(3)topological insulator(TI)nanofilms,which present distinct optical resonance in the near-infrared region.The result shows that the Bi_(2)Te_(3)TI material presents ultrahigh refractive indices of>6 at telecommunication wavelengths.The cavity thickness can approach 1/20 of the resonance wavelength,superior to those of planar cavities based on conventional Si and Ge high refractive index materials.Moreover,we observed an analog of the electromagnetically induced transparency(EIT)effect at telecommunication wavelengths by depositing the cavity on a photonic crystal.The EIT-like behavior is derived from the destructive interference coupling between the nanocavity resonance and Tamm plasmons.The spectral response depends on the nanocavity thickness,whose adjustment enables the generation of obvious Fano resonance.The experiments agree well with the simulations.This work will open a new door for ultrathin cavities and applications of TI materials in light control and devices.
基金
supported by the National Key R&D Program of China(Grant No.2022YFA1404800)
the National Natural Science Foundation of China(Grant Nos.11974283,61705186,and 11774290)
the Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2020JM-13)
the“Double First-Class”Construction Fund Project(Grant No.0206022GH0202)
the Fundamental Research Funds for the Central Universities(Grant No.D5000220175)
作者简介
Address all correspondence to:Hua Lu,hualu@nwpu.edu.cn,is as a professor at Northwestern Polytechnical University in China.He received his PhD from the Chinese Academy of Sciences.He was a postdoc fellow at Swinburne University of Technology in Australia,and then joined Northwestern Polytechnical University in 2015.His current research interest is focused on nanophotonics,plasmonics,and nanomaterials.To date,he has published more than 100 articles in professional journals,including Light Sci.Appl.,Adv.Photon.,Laser Photon.Rev.,and Small,with citation counts of>6400.He received the 13th Shaanxi Youth Science and Technology Award(2020)and was continuously selected as Elsevier’s Highly Cited Chinese Researcher(2021-2023);Address all correspondence to:Jianlin Zhao,jlzhao@nwpu.edu.cn,is a chief scientist at Northwestern Polytechnical University and the director of MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions.He has been selected as a fellow of the Chinese Optical Society and the executive editor-in-chief of Acta Optica Sinica.His research interests include micro-/nanophotonics,light-field manipulation,digital holography,and optical fiber sensing.To date,he has published three textbooks(sole author)and more than 500 articles in professional journals,including Science,Nat.Mater.,Adv.Mater.,Light Sci.Appl.,and Nat.Commun.,with citation counts of>13,000.He was continuously selected as Elsevier’s Highly Cited Chinese Researcher(2021-2023).
