Advancing broadband light structuring through single-size nanostructured all-dielectric meta-devices

Dielectric Supercell Metasurfaces for Generating Focused Higher-Order Poincaré Beams with the Residual Copolarization Component Eliminated

“…Because in the wavelength range in discussion, the refractive index n of a-Si:H varies in the small range, the meta-atoms still offer the propagation phases ϕ xx covering the range of 2π, and the phase change versus the eight selected meta-atoms is roughly in the same linear gradient for different wavelengths. , Thus, except for an additional constant phase, the propagation profiles for different wavelengths are approximately the same as for the main wavelength of 800 nm. With the geometric phase being wavelength-independent, the total phase profiles as the sum of the propagation and geometric phases are also approximately the same for all wavelengths, except for the additional constant. , Furthermore, under the illuminating light of different wavelengths, the propagation dispersion will cause the wavefronts to be focused at different focal lengths, forming the focused VBs with varied doughnut size. , This means that the metasurfaces are provided with the broadband response. However, in the strict sense, the variation of phase retardation |ϕ xx – ϕ yy | with wavelength may increase the residual copolarization components.…”

“…Specifically, to eliminate the copolarization spots, Shan et al proposed the metasurfaces using the continuous amplitude-modulated meta-fork gratings for vortex generation, Fu et al employed the positive and negative amplitude modulation of nanopolarizers in metasurface design in realization of the coaxial holographic images, and Zheng et al designed the metasurfaces by choosing the orientation angles of the meta-atoms for the projection of on-axis 3-layer holographic images. In some other studies, the residual copolarization components were not directly eliminated, but it was avoided by deflecting the light fields or images from the axis, while the copolarization component was left uneliminated. , This method has been used in the generation of the multichannel noncoaxial focused HOP beams. , Furthermore, for the output light fields of spatially homogeneous polarizations, the deflection and polarization filtering , may be combined, but the copolarization spot also cannot be fully eliminated.…”

Broadband all-dielectric meta-devices for visible perfect vortex beams generation

“…Recently, the realm of metasurfaces has risen as an up-and-coming contender for producing captivating optical phenomena, notably including PV beams [13]- [18]. Currently, metasurfaces have come into light as highly promising contenders for a multitude of applications, such as flat lenses [19]- [21], meta-holograms [22]- [28], multifunctional meta-devices [29]- [32], liquid crystal-based devices [33]- [35], structured light generation [36]- [38], circular dichroism spectroscopy [39]- [42] metaabsorbers [43]- [45], and intelligent surfaces [46]- [50].…”

An investigation of inorganic ETL materials for carbon-based HTL-free perovskite solar cell

“…To date, solar cells have entered the power generation pool very significantly, and their applications are acknowledged along with their unique advantages. On the other hand, miniaturized devices called metasurfaces played an important role in the realization of numerous exceptional devices and phenomena, including metalenses [8]- [10], polarization detection [11], metaholography [12]- [17], perfect vortex beam generators [18]- [21], structured light generation [22]- [25], meta-absorbers [26]- [29], reconfigurable intelligent surfaces [30]- [32], and solar cells [33]- [36]. At the very beginning of this journey, siliconbased solar cells were designed initially to have a low efficiency, which is subject to the Shockley-Queisser (SQ) limit [37], [38] in the form of thermalization and transmission losses (Figure 1) [39].…”