We study the impact of a spatially homogeneous yet non-stationary dielectric permittivity on the dynamical and spectral properties of light. Our choice of potential is motivated by the interest in PT-symmetric systems as an extension of quantum mechanics. Because we consider a homogeneous and non-stationary medium, PT symmetry reduces to time-reversal symmetry in the presence of balanced gain and loss. We construct the instantaneous amplitude and angular frequency of waves within the framework of Maxwell's equations and demonstrate the modulation of light amplification and attenuation associated with the well-defined temporal domains of gain and loss, respectively. Moreover, we predict the splitting of extrema of the angular frequency modulation and demonstrate the associated shrinkage of the modulation period. Our theory can be extended for investigating similar time-dependent effects with matter and acoustic waves in PT-symmetric structures.
Breaking the Limitations of Temporal Modulation via Mixed Continuity Conditions
School of Physics, Harbin Institute of Technology（哈尔滨工业大学物理学院）；Heilongjiang Provincial Key Laboratory of Plasma Physics and Application Technology（黑龙江省等离子体物理及应用技术重点实验室）；Heilongjiang Provincial Innovation Research Center for Plasma Physics and Application Technology（黑龙江省等离子体物理及应用技术创新研究中心）
Ultrafast, reconfigurable all-optical beam steering and spatial light modulation
Thomas J. Watson Laboratory of Applied Physics, California Institute of Technology（加州理工学院应用物理托马斯·J·沃森实验室）；Department of Mechanical Engineering, University of California, Berkeley（加州大学伯克利分校机械工程系）；School of Electrical and Computer Engineering, Faculty of Engineering, Tel-Aviv University（特拉维夫大学工程学院电气与计算机工程学院）
Full-Wave Harmonic Balance Framework for Dispersive Time-Varying Photonic Structures
School of Electrical and Computer Engineering, Georgia Institute of Technology（佐治亚理工学院电气与计算机工程学院）；School of Materials Science and Engineering, Georgia Institute of Technology（佐治亚理工学院材料科学与工程学院）
Fluctuational Quantum Electrodynamics of Dispersive Time-Varying Media
Universidad Autónoma de Madrid（马德里自治大学）；Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid（马德里自治大学凝聚态物理中心 (IFIMAC)）；Instituto Nicolás Cabrera (INC), Universidad Autónoma de Madrid（马德里自治大学尼古拉斯·卡布雷拉研究所 (INC)）
Deterministic time rewinding of waves in time-varying media
Research Institute of Basic Sciences, Ajou University（韩国亚洲大学基础科学研究院）；Department of Physics, Ajou University（韩国亚洲大学物理系）；School of Physics, Korea Institute for Advanced Study（韩国高等研究院物理学院）
Amplified up-conversion of electromagnetic waves using time-varying metasurfaces
ARC Centre of Excellence for Transformative Meta-Optical Systems (TMOS), Research School of Physics, The Australian National University（澳大利亚国立大学变革性超光学系统卓越研究中心物理研究学院）；Instituto de Telecomunicações and Department of Electronics, Telecommunications and Informatics, University of Aveiro（阿威罗大学电信研究所电子、电信与信息系）
Diffraction of waves by screens (apertures in screens) with time-varying dimensions. Time-varying Kirchhoff's integral representation for moving boundaries
Bound states in the continuum in multilayered time-varying metasurfaces
Karlsruhe Institute of Technology（卡尔斯鲁厄理工学院）；Institute of Theoretical Solid State Physics, Karlsruhe Institute of Technology（卡尔斯鲁厄理工学院理论固体物理研究所）；Institute for Analysis, Karlsruhe Institute of Technology（卡尔斯鲁厄理工学院分析学研究所）；Institute of Nanotechnology, Karlsruhe Institute of Technology（卡尔斯鲁厄理工学院纳米技术研究所）；Center for Integrated Quantum Science and Technology (IQST), Karlsruhe Institute of Technology（卡尔斯鲁厄理工学院综合量子科学与技术中心）
