Luminescence glass is a potential candidate for the light-emitting diodes (LEDs) applications. Here, we study the structural and optical properties of the Eu-, Tb-, and Dy-doped oxyfluoride silicate glasses for LEDs by means of X-ray diffraction, photoluminescence spectra, Commission Internationale de L'Eclairage (CIE) chromaticity coordinates, and correlated color temperatures (CCTs). The results show that the white light emission can be achieved in Eu/Tb/Dy codoped oxyfluoride silicate glasses under excitation by near-ultraviolet light due to the simultaneous generation of blue, green, yellow, and red-light wavelengths from Tb, Dy, and Eu ions. The optical performances can be tuned by varying the glass composition and excitation wavelength. Furthermore, we observed a remarkable emission spectral change for the Tb 3+ single-doped oxyfluoride silicate glasses. The 5 D 3 emission of Tb 3+ can be suppressed by introducing B 2 O 3 into the glass. The conversion of Eu 3+ to Eu 2+ takes place in Eu single-doped oxyfluoride aluminosilicate glasses. The creation of CaF 2 crystals enhances the conversion efficiency. In addition, energy transfers from Dy 3+ to Tb 3+ and Tb 3+ to Eu 3+ ions occurred in Eu/Tb/Dy codoped glasses, which can be confirmed by analyzing fluorescence spectra and energy level diagrams. Fig. 9. Schematic energy level diagrams of Eu 3+ , Tb 3+ , and Dy 3+ ions showing the energy transfer (ET) and cross-relaxation (CR) process.

states can generate structured spatial light fields via the comprehensive manipulations of the helical phase, polarization, and propagation of the light. Intuitively, the equal-weighted superposition of OAM states with TCs of opposite signs may generate spatial modes of petal-like intensity with nonzero or zero global OAMs, and superpositions of higher-order OAMs may produce wheel-like modes with azimuthal variations of intensity in high dimensions. A variety of methods or devices have been developed to enable the superposition of OAMs. These include liquid crystal q-plates, [1][2][3] spatial light modulators, [4,5] crystal prism pairs, [6] microscopic ring resonators, [7,8] and other optical elements. [9][10][11] Moreover, the progress in OAM superposition has brought about many important applications in classical physics and quantum sciences. Classical applications include particle trapping, [12] optical communications, [13,14] and relativistic laser-matter interactions. [15,16] In the quantum field, important advancements have been made in quantum communications, [17][18][19] quantum information processing, [20,21] and quantum calculations. [22,23] The potential to miniaturize superposed spatial modes of OAM to nanoscale is promising for the implementation of integrated on-chip devices. Metasurfaces consisting of monolayers of subwavelength metallic/dielectric structures have become an efficient way to manipulate light at the subwavelength scale. In recent several years, the study of metasurfaces has attracted great interest in areas as phase-controlled, [24] broadband vectorial holograms, [25] broadband achromatic metalenses, [26] and the coherent control of plasmonic spin-Hall effects. [27] The development of metasurfaces for the manipulation of OAM states has also been studied extensively. [28][29][30][31][32][33][34][35] In the past year, significant progress has been made in achieving arbitrarily controlled OAM superposition states via metasurface engineering. Devlin et al. have proposed the metasurface J-plate to realize the superposition of independent OAM states and to convert SAMs into total angular momentum states. [36] Using a reflective plasmonic metasurface, Yue et al. demonstrated various OAM superpositions in multiple channels by changing the polarization of the illumination. [37,38] By designing a nonlinear plasmonic metasurface for the simultaneous control of the OAM and SAM, Li et al. achieved the OAM superposition of the modes of the second Superposition of orbital angular momentum (OAM) states and the structured intensity are providing new approaches for manipulating optical information and light-matter interactions. While superposition of OAMs in free space has been well studied, further extensions to surface plasmon polariton (SPP) confined in near-field would be crucial for miniaturing and integrating platforms. Here, the plasmonic metasurfaces consisting of rotated nanoslits arranged in a segmented spiral are proposed to realize the superposition of two SPP OAM states. The nanoslit rota...

Nanoscale lattices of arbitrary orders are generated by truncated spiral metasurfaces combining geometric and dynamic phases.

Vector beams contain complex polarization structures and they are inherently non-separable in the polarization and spatial degrees of freedom. The spatially variant polarizations of vector beams have enabled many important applications in a variety of fields ranging from classical to quantum physics. In this study, we designed and realized a setup based on Mach-Zehnder interferometer for achieving the vector beams at arbitrary points of higher-order Poincaré sphere, through manipulating two eigenstates in the Mach-Zehnder interferometer system with the combined spiral phase plate. We demonstrated the generation of different kinds of higher-order Poincaré beams, including the beams at points on a latitude or longitude of higher-order Poincaré sphere, Bell states for |l| = 1 and |l| = 2, radially polarized beams of very high order with l = 16, etc. Vector beams of high quality and good accuracy are experimentally achieved, and the flexibility, feasibility and high efficiency of the setup are demonstrated by the practical performance.

Wavefield manipulation of surface plasmon polaritons (SPPs) is one of the fundamental subjects in nanophtonics. In this paper, based on the analyses of the plasmonic and photonic modes of the L-shaped slit samples with different widths, the dependence of the wavevector, amplitude and phase of the scattered wavefields on the slit width are experimentally determined. The excited plasmonic mode and photonic mode wavelets by arbitrary slit element is analyzed theoretically. Au ring-slits with different widths are also experimented as general slit structure to show the polarized patterns originated from the superimposition of the two modes, and the evolution of total and polarized intensity patterns with the ring-slit widths is studied systematically. The wavefield patterns of the polarization components are also calculated with the obtained components of wavefields and Huygens-Fresnel principle, and results of calculations and experiments are coincident. In addition, the results are validated by performing finite-difference time-domain simulations. The work may enhance the efficiency of slit engineering for SPP pattern manipulations and can be a helpful reference for the fabrication of nano-optics devices.