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Recently, a new type of metasurface, the induced-magnetism Huygens' metasurface, has attracted considerable attention due to its capability to manipulate electromagnetic waves. However, these studies mainly work in a passive way such that the functionalities are fixed once fabricated, limiting the device's adaptability for practical applications and future commercialization. To comply with potential applications, further research endeavors need to be exerted to advance the reconfigurability and practicality. Herein, an ultra-compact and dynamically tunable design strategy of an induced-magnetism Huygens' metasurface is proposed, whose basic unit is a pair of electric dipoles separated by a dielectric spacer and integrated with a varactor in each electric dipole. By simply changing the driven voltage of each unit, the transmission phase can be individually tuned in the near 2 π range; meanwhile, the transmission amplitude remains very high. As a proof-of-concept demonstration, an active magnetism induced Huygens' meta-lens is proposed to exhibit excellent dynamic wavefront manipulation performance. The proposed method may open an avenue toward planar lightweight low-cost dynamic wavefront manipulation devices. [ABSTRACT FROM AUTHOR]

Photonic gaps are the core of photonic crystals in the manipulation of light. However, in conventional photonic crystals composed of two types of dielectrics, the photonic gaps strongly depend on the angle of incidence, which limits their applications. In this Letter, we present the experimental demonstration of angle-independent gaps in the visible wavelength range in onedimensional photonic crystals composed of layered hyperbolic metamaterials (HMMs) and dielectrics. HMMs with anomalous wave-vector dispersion can tune the propagating phase of light to an unprecedented extent that usual dielectrics cannot attain. The HMM is mimicked by the layered titanium dioxide and silver with a subwavelength unit cell. Based on the phase-variation compensation effect between the HMM and the dielectric, an angle-independent gap is experimentally realized, which agrees well with the simulated one. This angle-independent gap is very useful in the design of photonic devices such as omnidirectional reflectors with fixed bandwidth or all-angle filters. [ABSTRACT FROM AUTHOR]

We exploit theoretically the propagation properties of electromagnetic waves in nanoscale one-dimensional superconducting photonic crystal. The Wannier Stark ladders can be formed in the photonic crystal by varying the thickness of the dielectric layers linearly across the structure. The dynamics behavior of a Gaussian pulse transmitting through the structure is simulated theoretically. We find that photons undergo Bloch oscillations inside tilted photonic bands and the Bloch oscillations are sensitive to the change of temperature in the range of 3–8 K. It is demonstrated that our structure is possible to realize tunable optical Bloch oscillations by controlling the temperature of superconducting material. [ABSTRACT FROM AUTHOR]