Thermal energy dependent transient permittivity of epsilon-near-zero material

Wang, Heng1,2,3; Sun, Lixun1,2; Du, Kang1,2; Zhang, Wending1,2; Chua, SooJin1,2,5,6; Li, Guixin3,4; Mei, Ting1,2

2022-08-01

10.1007/s11433-022-1913-5

Science China-Physics Mechanics & Astronomy   影响因子和分区

1674-7348

1869-1927

Transparent conductive oxides exhibit attractive optical nonlinearity with ultrafast response and giant refractive index change near the epsilon-near-zero (ENZ) wavelength, originating from the intraband dynamics of conduction electrons. The optical nonlinearity of ENZ materials has been explained by using the overall-effective-mass and the overall-scattering-time of electrons in the extended Drude model. However, their response to optical excitation is yet the last building block to complete the theory. In this paper, the concept of thermal energy is theoretically proposed to account for the total energy of conduction electrons exceeding their thermal equilibrium value. The time-varying thermal energy is adopted to describe the transient optical response of indium-tin-oxide (ITO), a typical ENZ material. A spectrally-resolved femtosecond pump-probe experiment was conducted to verify our theory. By correlating the thermal energy with the pumping density, both the giant change and the transient response of the permittivity of ITO can be predicted. The results in this work provide a new methodology to describe the transient permittivities of ENZ materials, which will benefit the design of ENZ-based nonlinear photonic devices.

epsilon-near-zero optical nonlinearity transient response thermal energy hot electron indium tin oxide

SCI ; EI

英语

其他

National Natural Science Foundation of China["91950207","12174310","61805157","11974282"]

Physics

Physics, Multidisciplinary

WOS:000824699600004

SCIENCE PRESS

20222912365547

Charge transfer ; Electrons ; Indium compounds ; Nonlinear optics ; Permittivity ; Photonic devices ; Refractive index ; Tin oxides ; Transient analysis

Light/Optics:741.1 ; Nonlinear Optics:741.1.1 ; Optical Devices and Systems:741.3 ; Chemical Reactions:802.2 ; Inorganic Compounds:804.2

Web of Science

1.Northwestern Polytech Univ, MOE Key Lab Mat Phys & Chem Extraordinary Condit, Sch Phys Sci & Technol, Xian 710129, Peoples R China
2.Northwestern Polytech Univ, Shaanxi Key Lab Opt Informat Technol, Sch Phys Sci & Technol, Xian 710129, Peoples R China
3.Southern Univ Sci & Technol, Dept Mat Sci & Engn, Shenzhen 518055, Peoples R China
4.Southern Univ Sci & Technol, Shenzhen Inst Quantum Sci & Engn, Shenzhen 518055, Peoples R China
5.Natl Univ Singapore, Dept Elect & Comp Engn, Singapore 117583, Singapore
6.Singapore MIT Alliance Res & Technol SMART, LEES Program, Singapore 138602, Singapore

Wang, Heng,Sun, Lixun,Du, Kang,et al. Thermal energy dependent transient permittivity of epsilon-near-zero material[J]. Science China-Physics Mechanics & Astronomy,2022,65(8).

Wang, Heng.,Sun, Lixun.,Du, Kang.,Zhang, Wending.,Chua, SooJin.,...&Mei, Ting.(2022).Thermal energy dependent transient permittivity of epsilon-near-zero material.Science China-Physics Mechanics & Astronomy,65(8).

Wang, Heng,et al."Thermal energy dependent transient permittivity of epsilon-near-zero material".Science China-Physics Mechanics & Astronomy 65.8(2022).