We present an experimental demonstration of self-guiding electromagnetic edge states existing along the zigzag edge of a honeycomb magnetic photonic crystal. These edge states are shown to possess unidirectional propagation characteristics that are robust against various types of defects and obstacles. In particular, they allow for the unidirectional transport of electromagnetic energy without requiring an ancillary cladding layer.

Topological insulators have unconventional gapless edge states where disorder-induced back-scattering is suppressed. In photonics, such edge states lead to unidirectional waveguides which are useful for integrated photonic circuitry. Cavity modes, another type of fundamental component in photonic chips, however, are not protected by band topology because of their lower dimensions. Here we demonstrate that concurrent wavevector space and real-space topology, dubbed as dual-topology, can lead to light-trapping in lower dimensions. The resultant photonic-bound state emerges as a Jackiw–Rebbi soliton mode localized on a dislocation in a two-dimensional photonic crystal, as proposed theoretically and discovered experimentally. Such a strongly confined cavity mode is found to be robust against perturbations. Our study unveils a mechanism for topological light-trapping in lower dimensions, which is invaluable for fundamental physics and various applications in photonics.

The propagation of microwaves through a chiral metamaterial based on a magnetic dimer is experimentally studied. As proposed by our previous theoretical model, two resonance peaks are obtained in the transmission spectrum; these originate from the hybridization effect of magnetic resonance modes in this system. Optical activity is also observed in the transmission wave. The polarization state dramatically changes around the resonance frequency: the transmitted wave becomes elliptically polarized with its major polarization axis approximately perpendicular to that of the linear incident wave. This coupled magnetic dimer system provides a practical method to optically design tunable active medium and device.

Nanocomposite fiber is one of the most fascinating materials with broad applications. In the present work, nanocomposite fibers were prepared by using a low-cost, simple, and “green” process as follows. Regenerated cellulose (RC) fibers were spun from cellulose dope in 7 wt % NaOH/12 wt % urea aqueous solution precooled to −12 °C, and magnetic nanocomposite fibers were fabricated by introducing in situ synthesized iron oxide (Fe2O3) nanoparticles into the wet cellulose fibers spun via a small-scale pilot machine. The results from transmission electron microscopy and X-ray diffraction showed that the magnetic Fe2O3 nanoparticles with a mean diameter of 18 nm were uniformly dispersed in the cellulose matrix. The composite fibers exhibited a higher mechanical strength than RC fibers, as well as a strong capability to absorb UV rays, superparamagnetic properties, and a relatively high dielectric constant. FT-IR results indicated that there is a strong interaction between cellulose and Fe2O3 in the fibers, leading to the formation and stabilization of the novel magnetic materials. The nanocomposite fibers will be important for the development of functional fabrics and protective clothing for ultraviolet radiation or microwaves.