Transmission-reflection decoupling of non-Hermitian photonic doping epsilon-near-zero media

We present a novel method to achieve the decoupling between the transmission and reflection waves of non-Hermitian doped epsilon-near-zero(ENZ)media by inserting a dielectric slit into the structure.Our method also allows for independent control over the amplitude and the phase of both the transmission and reflection waves through few dopants,enabling us to achieve various optical effects,such as perfect absorption,high-gain reflection without transmission,reflectionless high-gain transmission and reflectionless total transmission with different phases.By manipulating the permittivity of dopants with extremely low loss or gain,we can realize these effects in the same configuration.We also extend this principle to multi-port doped ENZ structures and design a highly reconfigurable and reflectionless signal distributor and generator that can split,amplify,decay and phase-shift the input signal in any desired way.Our method overcomes limitations of optical manipulation in doped ENZ caused by the interdependent nature of the transmission and reflection,and has potential applications in novel photonic devices.

Ultra-high extinction-ratio light modulation by electrically tunable metasurface using dual epsilon-near-zero resonances

The lossy nature of indium tin oxide(ITO) at epsilon-near-zero(ENZ) wavelength is used to design an electrically tunable metasurface absorber. The metasurface unit cell is constructed of a circular resonator comprising two ITO discs and a high dielectric constant perovskite barium strontium titanate(BST) film. The ENZ wavelength in the accumulation and depletion layers of ITO discs is controlled by applying a single bias voltage. The coupling of magnetic dipole resonance with the ENZ wavelength inside the accumulation layer of ITO film causes total absorption of reflected light. The reflection amplitude can achieve ~84 d B or ~99.99% modulation depth in the operation wavelength of 820 nm at a bias voltage of-2.5 V. Moreover, the metasurface is insensitive to the polarization of the incident light due to the circular design of resonators and the symmetrical design of bias connections.

基于介电常数近零媒质的舰船隐身材料微波传感器

舰船雷达波材料技术是减缩水面舰船雷达波散射截面,提高全舰雷达波隐身性能的重要手段,准确、有效地测量隐身吸波材料的复介电常数对舰船雷达波隐身的研究起重要作用。本文提出一种基于介电常数近零(ENZ)媒质的高性能微波传感器,通过将隐身吸波材料放置于传感器的一端或两端,基于谐振法进行复介电常数的精确测量。该传感器结构简单、灵敏度高,具有小型化、易集成、低成本和易共形测量等优点。