73 research outputs found
Caustic analysis of partially coherent self-accelerating beams: Investigating self-healing property
We employed caustic theory to analyze the propagation dynamics of partially
coherent self-accelerating beams such as self-healing of partially coherent
Airy beams. Our findings revealed that as the spatial coherence decreases, the
self-healing ability of beams increases. This result have been demonstrated
both in simulation and experiment. This is an innovative application of the
caustic theory to the field of partially coherent structured beams, and
provides a comprehensive understanding of self-healing property. Our results
have significant implications for practical applications of partially coherent
beams in fields such as optical communication, encryption, and imaging.Comment: 9 pages, 4 figure
All-Dielectric Structural Coloration Empowered by Bound States in the Continuum
The technological requirements of low-power and high-fidelity color displays
have been instrumental in driving research into advanced coloration
technologies. At the forefront of these developments is the implementation of
dye-free coloration techniques, which overcome previous constraints related to
insufficient resolution and color fading. In this context, resonant dielectric
nanostructures have emerged as a promising paradigm, showing great potential
for high efficiency, remarkably high color saturation, wide gamut palette, and
realistic image reproduction. However, they still face limitations related to
color accuracy, purity, and simultaneous brightness tunability. Here, we
demonstrate an all-dielectric metasurface empowered by photonic bound states in
the continuum (BICs), which supports sharp resonances throughout the visible
spectral range, ideally suited for producing a wide range of structural colors.
The metasurface design consists of titanium dioxide (TiO2) ellipses with
carefully controlled sizes and geometrical asymmetry, allowing versatile and
on-demand variation of the brightness and hue of the output colors,
respectively.Comment: Main text and supporting information, 40 pages, 4 Figures in the
manuscript + 12 Figures in the supporting informatio
Simple Synthesis and Growth Mechanism of Core/Shell CdSe/ SiO
Core-shell-structured CdSe/SiOx nanowires were synthesized on an equilateral triangle Si (111) substrate through a simple one-step thermal evaporation process. SEM, TEM, and XRD investigations confirmed the core-shell structure; that is, the core zone is single crystalline CdSe and the shell zone is SiOx amorphous layer and CdSe core was grown along (001) direction. Two-stage growth process was present to explain the growth mechanism of the core/shell nanwires. The silicon substrate of designed equilateral triangle providing the silicon source is the key factor to form the core-shell nanowires, which is significant for fabrication of nanowire-core sheathed with a silica system. The PL of the product studied at room temperature showed two emission bands around 715 and 560 nm, which originate from the band-band transition of CdSe cores and the amorphous SiOx shells, respectively
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