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Edge states in photonic heterostructures composed of metal layers and all-dielectric one-dimensional photonic crystals (1DPCs) will shift toward short wavelengths (blueshift) with the increase in the incident angle for both transverses magnetic (TM) and transverse electric (TE) polarizations. However, we achieve redshift edge states for TM polarization and blueshift edge states for TE polarization in heterostructures composed of metal layers and 1DPCs containing layered hyperbolic metamaterials. Owing to the opposite wavelength shift of the edge states for two orthogonal polarizations, the ellipsometric phase will change dramatically around the edge state wavelength in a broad angle range. Based on this wide-angle phase singularity property, we propose a biosensor which can work with high refractive index resolution in a broad angle range.

We theoretically and experimentally investigate the wide-angle perfect absorptance in a photonic heterostructure composed of a metal film and a truncated photonic crystal (PC) with layered hyperbolic metamaterials (HMMs) in the near ultraviolet and visible regions. The wide-angle perfect optical absorption depends on the dispersionless Tamm plasmon polarition (TPP) under TM polarization, which originates from reflection phase compensation condition between the metal and the truncated PC with HMMs. Our experimental results show nearly perfect absorptance over 0.91 in an angle range of 0-45 degree, which facilitates the design of perfect optical absorbers working in a wide angle range.

We propose a topological description for gaps of one-dimensional symmetric all-dielectric photonic crystals (PCs). It is shown that, in the propagating direction, the effective electromagnetic parameters of PCs can be derived from one unit cell with mirror symmetry. Besides, at the frequencies of gaps, these symmetric PCs can be described as photonic insulators with effective negative permittivity or negative permeability. Moreover, based on the mapping of Maxwell's equations to the Dirac equation and the band inversion achieved by tuning the material and structural parameters, we demonstrate that the gaps of PCs with effective negative permittivity or negative permeability possess different topological orders. Lastly, we show that a bound state is robust against the disorder under a zero-average-effective-mass condition in a heterostructure made of two PCs with different topological orders.

We propose a scheme for subwavelength electromagnetic switch by employing nonlinear meta-atom. Bistable response is conceptually demonstrated on a microwave transmission line, which is side-coupled to a varactor-loaded split ring resonator acting as a nonlinear meta-atom. Calculations and experiments show that by applying conductive coupling instead of near-field interaction between the transmission line and the nonlinear meta-atom, switch performances are improved. The switch threshold of low to -5.8 dBm and the transmission contrast of up to 4.0 dB between the two bistable states were achieved. Subwavelength size of our switch should be useful for miniaturization of integrated optical nanocircuits.

We theoretically investigate the feasibility of constructing compact and highly efficient all-optical diodes (AODs) based on light tunneling mechanism in heterostructures. Due to light tunneling behaviors in heterostructures with one-dimensional photonic crystals (1D PC) and lossy metallic film, not only very large nonlinear permittivity of metal can be utilized sufficiently but also the structures with strongly nonreciprocal electric field distributions can be constructed. Finally we design a composite structure consisting of 1D PC-metal heterostructures to achieve the optimal unidirectional light transmission with 0.984 transmission contrasts, 42% transmission and 0.93 GW/cm(2) operating light power at working wavelength 557.2nm.

Different discrete soliton states in optical waveguide lattices are studied theoretically for the different external conditions such as the biased field, lattice spacing and the position of the input pulse. It is demonstrated that the discrete solitons can be formed in an appropriate biased field and exhibit different discrete properties in different biased field. The results also indicate that lattice spacing and the position of input pulse can affect apparently the discreteness of discrete solitons. If changing the ratio of the waist width of input beam to lattice period, the discrete solitons will be excited in more or less channels. In addition, the increase of lattice intensity almost does not affect the propagation behavior of soliton.