Highlights Nano

Topological photonics with ZnO (2019)

Voigt points represent propagation directions in anisotropic crystals along which optical modes degenerate, leading to a single circularly polarized eigenmode.
By employing an appropriately-designed dielectric, anisotropic optical microcavity based on nonpolar ZnO/ZnMgO Bragg reflectors, we have been able to implement a non-Hermitian system and mimic thereby the behavior of Voigt points in natural crystals.


Epitaxial growth of Fe3O4 on ZnO nanostructures (2019)

There is currently a worldwide effort to integrate semiconductors and magnetic materials, as an efficient spin injection and detection of spin in semiconductors is essential to the field of spintronics, but remains an unsolved issue.
The research project “SPINOXIDE” aims at taking advantage of both ZnO compatibility for the epitaxy of highly spin-polarized oxide ferromagnets and the potentially exceptional spin coherence lengths and spin lifetimes in ZnO nanostructures.


Vectorial Holography (2019)

Polarization reconstruction, which is based on the superposition of two orthogonal polarization bases, has been widely used in optical science. Circular polarization (CP), respectively linear polarization (LP), can be generated based on the superposition of two orthogonal LP, respectively CP.
However, full-polarization reconstruction cannot be obtained based on such phase-only difference be-tween two orthogonal ba-ses and its application to arbitrary wavefront control have not been realized.


Metasurface integrated Vertical Cavity Surface Emitting Lasers (2019)

Vertical-cavity surface-emitting laser (VCSEL) has experienced a soaring development over the last 30 years and become one of the most versatile laser sources for a large number of applications.
The exploding development of modern optoelectronic technologies places stringent requirements for lower power consumption devices with high efficiency and more compact integrated system. However, due to the narrow aperture of the laser, their emission is generally highly divergent, spreading the signal after only few hundreds of microns from the laser source.


Polariton lasing competition (2018)

Polaritons are the quasiparticles resulting from the strong coupling between a confined photonic mode and an excitonic resonance. Since their observation in 1992, most studies have been carried out in vertical microcavities, which are usually fabricated by introducing an active region between two Bragg mirrors.


Hybrid-metasurfaces (2018)

Metasurfaces control various properties of light via scattering across a large number of subwavelength-spaced nanostructures. Wavelength-dependent diffraction and resonant scattering effects usually limit their working operation wavelengths. In refractive optics, chromatic dispersion is a significant problem and is generally treated by cascading multiple lenses into achromatic doublets, triplets, and so on.


Optical phase transition in semiconductor quantum metamaterials (2018)

The direction of refracted light at an interface between two media generally follows the conventional Snell-Descartes law. Bystacking subwavelength-thick metallic and dielectric layers to form metamaterials, it is possible to realize unexpected behavior such as negative refraction.

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