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Spin Angular Momentum Controlled Multifunctional Alla??Dielectric Metasurface Doublet
摘要： Lenses are the most important components of portable and integrable optical systems. Due to the inherent limitation of system sizes, external accessories are required for realizing additional functions such as close-up or telegraph imaging, making the entire system complicated and cumbersome. Herein, based on the developments of metalenses, a spin angular momentum controlled multifunctional camera system is reported. Two types of metalens with high efficiencies are designed and fabricated for circularly polarized and nonpolarized light, respectively. By combining them into a doublet, multiple functions are realized beyond a camera lens. For left-handed circular polarization light, the doublet works as a compound microscope with a magnification factor of 20 and a resolution of 1.07 μm. The system switches to a Galileo telescope when the incident light turns to be right-handed circularly polarized. This research shall extend and strengthen the practical applications of metasurfaces in portable imaging systems as well as the integrated sensing terminals.
关键词： lens doublet,Galileo telescope,magnification,metalens,camera lens
更新于2025-09-23 15:21:01
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Multilayer Non-interacting Dielectric Metasurfaces For Multiwavelength Metaoptics
摘要： Metasurfaces provide a versatile platform for manipulating the wavefront of light using planar nanostructured surfaces. Transmissive metasurfaces, with full 2π phase control, are a particularly attractive platform for replacing conventional optical elements due to their small footprint and broad functionality. However, the operational bandwidth of metasurfaces has been a critical limitation and is directly connected to either their resonant response or the diffractive dispersion of their lattice. While multiwavelength and continuous band operation have been demonstrated, the elements suffer from either low efficiency, reduced imaging quality, or limited element size. Here, we propose a platform that provides for multiwavelength operation by employing tightly spaced multilayer dielectric metasurfaces. As a proof of concept, we demonstrate a multiwavelength metalens doublet (NA=0.42) with focusing efficiencies of 38% and 52% at wavelengths of 1180 nm and 1680 nm, respectively. We further show how this approach can be extended to three wavelength metalenses as well as a spectral splitter. This approach could find applications in fluorescent microscopy, digital imaging, and color routing.
关键词： Multiwavelength metalens,spectrum splitter,metasurface doublet,polarization-insensitive
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 10th International Symposium on Power Electronics for Distributed Generation Systems (PEDG) - Xi'an, China (2019.6.3-2019.6.6)] 2019 IEEE 10th International Symposium on Power Electronics for Distributed Generation Systems (PEDG) - A Short-term Photovoltaic Output Prediction Method Based on Improved PSO-RVM Algorithm
摘要： The memristor was first theorized as an electrical element, which provided the missing link between the charge and the flux. Due to the advantages of nano-scale size, multiple interconnected memristors have demonstrated unique overall characteristics, which are ideal for the utilization in neuromorphic systems. However, compared with the individual memristor circuit, a little work is explored about the overall behavior of the multiple memristive systems. In particular, the lack of a fault diagnosis approach for composite memristive network structures makes all the corresponding applications unstable and shaky. In this paper, the extraordinary properties of multiple memristor circuits are further investigated with comprehensive formula derivation and scientific computer simulations. Furthermore, a special feedback-control doublet generator is designed for implementing the fuzzy-based parametric fault diagnosis of multiple memristor circuits, which offers huge benefits in terms of accuracy and time consumption. Finally, the entire scheme is validated by an illustrative example.
关键词： Multiple memristor circuits,parametric fault diagnosis,feedback-control,doublet generator,fuzzy-based
更新于2025-09-19 17:13:59
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The triplet mechanism of electron spin polarization in moderately coupled triplet-doublet rigid complexes as a source of the enhanced +1/2 ???1/2 transitions
摘要： The light-induced electron spin polarization generated in the excited quartet and doublet states of a system consisting of a chromophore with an attached radical is investigated theoretically. Excitation of the chromophore and subsequent relaxation leads to a coupled triplet-doublet spin system. In many such systems, the electronic coupling between the triplet and doublet spins is expected to be strong enough to split the spin system into so-called trip-doublet and trip-quartet states but sufficiently weak that it does not promote significant mixing between the sing-doublet and trip-doublet states. In such moderately coupled systems, the sing-doublet can relax to the trip-doublet and trip-quartet states by spin-orbit coupling mediated intersystem crossing within the chromophore. An analytical expression is derived for the intensity of the polarization generated by this mechanism for the ms = +1/2 ? ?1/2 electron paramagnetic resonance transitions of the trip-doublet and trip-quartet states. The expression shows that the intensity and sign of the polarization depend strongly on ratio jω = 3J/ω0 between the triplet-doublet exchange interaction J and the Zeeman energy ω0. The polarization becomes undefined when jω = 1 and when jω = 2 because level-anticrossings between the trip-doublet and trip-quartet sublevels occur. The sign of the polarization is also found to change above and below these values. Thus, for such moderately coupled systems, the sign of the polarization and its Zeeman energy dependence can be used to estimate the magnitude of the exchange coupling.
关键词： electron spin polarization,spin-orbit coupling,Zeeman energy,exchange interaction,triplet-doublet complexes
更新于2025-09-12 10:27:22
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[IEEE 2017 IEEE Workshop on Recent Advances in Photonics (WRAP) - Hyderabad (2017.12.18-2017.12.19)] 2017 IEEE Workshop on Recent Advances in Photonics (WRAP) - Utilization of Segmented Cladding Fiber for the Generation of High Energy Femtosecond Pulse Trains
摘要： Generation of high-peak-power, femtosecond pulse train and pulse doublet has been numerically demonstrated by exponentially decreasing the dispersion along the length of the large-mode-area segmented-cladding fiber. Such pulse trains find applications in various nonlinear optical processes.
关键词： pulse doublet,femtosecond pulses,large mode area fiber,pulse train,Segmented cladding fiber
更新于2025-09-10 09:29:36
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Highly Efficient Fluorescent Organic Light-Emitting Devices Using a Luminescent Radical as the Sensitizer
摘要： In traditional fluorescent organic light-emitting diodes (OLEDs), the upper limit of internal quantum efficiency (IQE) is only 25% because 75 % triplet excitons created on the fluorescent dyes are non-luminous. Here, luminescent radicals are proposed as the sensitizer. Under ideal conditions, electrons and holes firstly recombine on the sensitizer molecule to create doublet excitons, then through energy transfer to generate singlet excitons on the fluorescent dye, finally via radiative decay to emit light. The upper limit of IQE can theoretically reach 100%. As an example, the maximum external quantum efficiency (EQE) of a fluorescent OLED sensitized by a luminescent radical, TTM-1Cz, has reached 8.1%, which is much higher than the upper limit of EQE of traditional fluorensenct OLEDs. Our results suggest a new route to realize highly efficient fluorescent OLEDs.
关键词： organic light-emitting device,doublet,luminescent radical,sensitize,deep-red
更新于2025-09-04 15:30:14