Herein, stacked nanosheets of barium and antimony are fabricated using a vacuum deposition technique under a vacuum pressure of 10-5 mbar onto cleaned glass substrates. The Zintl Ba/Sb nanosheets exhibit an amorphous ...
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Herein, stacked nanosheets of barium and antimony are fabricated using a vacuum deposition technique under a vacuum pressure of 10-5 mbar onto cleaned glass substrates. The Zintl Ba/Sb nanosheets exhibit an amorphous nature of growth with equal atomic contents. Notably, they present interesting properties such as low average roughness, high light transmittance and absorption, and low reflectance. Two optical transitions within energy bands with values of 3.40 eV and 0.75 eV are determined for these stacked nanosheets. Additionally, Ba/Sb nanosheets displayed dielectric lens and optical filter characteristics with high optical conductivity exceeding 5.0 (Omega cm)-1, 20 (Omega cm)-1, and 100 (Omega cm)-1 in the infrared, visible, and ultraviolet ranges of light, respectively. The optical conductivity parameters, including the free charge carrier density, drift mobility, and plasmon frequency, exhibit values in the ranges of 1.3-25x1019 cm-3, 3.53-9.41 cm2/versus, and 3.92-17.18 GHz, respectively. Moreover, Ba/Sb nanosheets display characteristics of terahertz band filters, demonstrating terahertz cutoff frequency values of 18-100 THz in the incident photon energy range of 1.13-3.64 eV. On the other hand, temperature-dependent electrical conductivity measurements on these stacked nanosheets reveal the domination of two impurity levels centered at 136 meV and 500 meV, with one being dominant below and the other above 380 K, respectively. The features of the Ba/Sb nanosheets reported here highlight their potential as optical filters, surface plasmon resonators, and terahertz band filters.
We propose an efficient, nonreciprocal single-photon device that achieves single-photon routing and frequency conversion through chiral coupling of two one-dimensional waveguides with a four-level atom. Photons incomi...
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We propose an efficient, nonreciprocal single-photon device that achieves single-photon routing and frequency conversion through chiral coupling of two one-dimensional waveguides with a four-level atom. Photons incoming from one port can be definitely directed to another port. However, the photon frequency conversion has been achieved only when the single photons are transferred from one waveguide to the other, and its probability can reach unity. Applied the on-demand classical field to drive an atom, the transmission quantum tunneling path can be turned off and on by exploiting the Autler-Townes splitting mechanism. Our results illustrate the potential of our device for applications in a quantum network.
The notch filter plays a crucial role as a protective component in microwave diagnostics, primarily by addressing issues related to catastrophic interference. Designed for millimeter-wave diagnostics on the stellarato...
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The notch filter plays a crucial role as a protective component in microwave diagnostics, primarily by addressing issues related to catastrophic interference. Designed for millimeter-wave diagnostics on the stellarator Wendelstein 7-X (W7-X), a WR-6 waveguide-based notch filter has been successfully developed to effectively isolate leakage from auxiliary heating gyrotrons operating at 140 GHz. The filter incorporates cylindrical cavities resonating at 140 GHz for the TE (11p) mode, with coupling structures that are designed and optimized for high-efficiency coupling. This configuration simplifies fabrication, thereby ensuring high-yield production. Experimental fabrication and in-house characterization confirm the notch filter's exceptional performance, with over 60 dB rejection in the vicinity of 140 GHz and low insertion loss (< 2 dB) above and below the notch frequency across a broad frequency bandwidth (121-138 GHz, 142-163 GHz). The utilization of this high-frequency structure fabrication technology can be applied to millimeter-wave diagnostics on other machines. In addition to the design elements of the notch filter, this paper also provides a detailed discussion of the fabrication process and methodology.
Since the invention of inverse vulcanization and high sulfur content polymers, termed Chalcogenide Hybrid Inorganic/Organic Polymers , the application of these polymers as optical materials for IR optics & photoni...
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Since the invention of inverse vulcanization and high sulfur content polymers, termed Chalcogenide Hybrid Inorganic/Organic Polymers , the application of these polymers as optical materials for IR optics & photonics has garnered interest from groups around the world. Earlier publications and review papers have focused on the polymer chemistry aspects of inverse vulcanization, however, recent work in the past decade has seen tremendous new advances in polymer processing, rheology, and optical component (nano-micro) fabrication of lenses and photonic devices across the infrared spectrum. There is an urgent need for a review surveying both new polymer chemistry and polymer engineering aspects of this important new field, for the integration of these new optical polymers into imaging, communications, and sensing systems. In this submission, we review the fabrication and polymer processing of inverse vulcanized organopolysulfides made from elemental sulfur for IR optics and photonics. We survey recent work in the SWIR and MWIR spectrum for the development of integrated photonics devices using high sulfur content polymers, along with the fabrication and testing of LWIR bulk plastic optics using this new class of optical polymers. (c) 2024 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Millimeter-scale slide optical waveguides (OWGs) show the potential to break the barrier of easy-to-use and versatility for total internal reflection (TIR) fluorescence technology. In this paper, multi-frequency struc...
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Millimeter-scale slide optical waveguides (OWGs) show the potential to break the barrier of easy-to-use and versatility for total internal reflection (TIR) fluorescence technology. In this paper, multi-frequency structured illumination (SI) patterns resulting from the evanescent field (EF) on the surface of a millimeter-scale polymer slide OWG are observed by measuring the fluorescence intensity distribution of fluorescent dyes deposited on the top of theOWG. The frequency, intensity, and stability of the SI patterns show a strong dependence on the coupling angle of the incident light (changing with the incident position). The distribution of multi-frequency SI patterns in the frequency space is demonstrated for different numerical aperture (NA) imaging systems (NA= 0.3, 0.6, and 0.8), indicating the potential for enhanced resolution for low NA systems with a simple and cheap polymer slide. (c) 2024 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.
Hyperbolic metamaterials comprised of an array of plasmonic nanorods provide a unique platform for designing optical sensors and integrating nonlinear and active nanophotonic functionalities. In this work, the wavegui...
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Hyperbolic metamaterials comprised of an array of plasmonic nanorods provide a unique platform for designing optical sensors and integrating nonlinear and active nanophotonic functionalities. In this work, the waveguiding properties and mode structure of planar anisotropic metamaterial waveguides are characterized experimentally and theoretically. While ordinary modes are the typical guided modes of the highly anisotropic waveguides, extraordinary modes, below the effective plasma frequency, exist in a hyperbolic metamaterial slab in the form of bulk plasmon-polaritons, in analogy to planar-cavity exciton-polaritons in semiconductors. They may have very low or negative group velocity with high effective refractive indices (up to 10) and have an unusual cut-off from the high-frequency side, providing deep-subwavelength ((0)/6-(0)/8 waveguide thickness) single-mode guiding. These properties, dictated by the hyperbolic anisotropy of the metamaterial, may be tuned by altering the geometrical parameters of the nanorod composite.
Waveguide-integrated on-chip meta-optics exhibit a promising platform for achieving high-performance and compact optical display devices. However, heading toward advanced wearable smart display technology, its broad i...
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Waveguide-integrated on-chip meta-optics exhibit a promising platform for achieving high-performance and compact optical display devices. However, heading toward advanced wearable smart display technology, its broad implementation is critically restricted by the lack of practical active tuning capability. Despite previous endeavors, on-chip meta-optics still face crucial challenges in achieving any arbitrary vectorial wavefront with dynamic switchable ability. Here, a practical liquid crystal (LC)-driven on-chip metasurface integrated on a waveguide is proposed and demonstrated for dynamic vectorial augmented reality (AR) meta-holograms. By engineering the on-chip meta-diatoms at the nanoscale, the simultaneous modulation of arbitrary polarization and phase of the out-coupling lightwave can be achieved for up to nine-channel fully polarized vectorial meta-holograms. As a proof of concept, in combination with an electrical-driven LC tuning platform, integrated on-chip meta-optics can actively switch holographic images floating in the actual-world scene in real-time as dynamic AR meta-displays. Moreover, owing to the on-chip optical propagation scheme, the projected AR holograms are uniquely free from zero-order diffraction interference. It is envisioned that such on-chip dynamic vectorial meta-displays integrated with the LC platform allow for miniaturized integration and promise potential applications in advanced intelligent dynamic displays, multiplexing information storage/encryption, and next-generation wearable AR displays.
Confinement of the light at the subwavelength scale makes photonic devices more efficient in applications such as optical filtering, switching, and sensing with their low dimensions. Metal-insulator- metal waveguide-b...
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Confinement of the light at the subwavelength scale makes photonic devices more efficient in applications such as optical filtering, switching, and sensing with their low dimensions. Metal-insulator- metal waveguide-based configurations present many paths for manipulating light at the wide range of the electromagnetic spectrum. For that purpose, in this study, a wavelength demultiplexer (WDM) based on a metal-insulator-metal (MIM) waveguide is numerically investigated by finite difference time domain (FDTD) method. Proposed WDMs have cascade polygon resonators. After optimizing the fundamental filter, this structure is formed as 1xN demultiplexers. The proposed demultiplexers have two- and three channels. The minimum full width at half-maximum (FWHM) value for these channels is 20.02 nm and the maximum quality factor value is 47.7 at 954.9 nm wavelength. The minimum crosstalk value is obtained as -30.37 dB for this study. The proposed 1xN demultiplexers have potential tools to design low-cost integrated optical circuits for specific wavelengths.
We propose and demonstrate an accurate method of measuring the effective refractive index of silicon-on-insulator waveguides. By conducting the combined analysis to the troughs' wavelength in spectra of Mach-Zehnd...
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We propose and demonstrate an accurate method of measuring the effective refractive index of silicon-on-insulator waveguides. By conducting the combined analysis to the troughs' wavelength in spectra of Mach-Zehnder interferometers on chip. The wavelength-dependent and temperature-dependent effective refractive index of the fabricated waveguides are measured experimentally, and obtained the thermo-optic coefficient of silicon-on-insulator waveguides is about 2x10(-4) /degree celsius in the 1550 nm communication band. The maximum measurement error for effective and group refractive index respectively are 1.5x10(-5) and 1.5x10(-3) obtained by numerical simulation. And an improved method for taking value of the free spectral range was discussed to obtain a more accurate group refractive index. It proves a fast and lost-cost measurement way to evaluate key optical parameters of waveguide, which can indicate the quality of fabrication process and optimize photonic components.
We propose a new, to the best of our knowledge, mechanism to realize topological phase transition, that is, in a hexagonal star-like honeycomb lattice photonic crystal (PC), the optical quantum spin Hall effect (QSHE)...
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We propose a new, to the best of our knowledge, mechanism to realize topological phase transition, that is, in a hexagonal star-like honeycomb lattice photonic crystal (PC), the optical quantum spin Hall effect (QSHE) can be realized by changing the materials of the outer or inner ring dielectric rods in the cells. We calculated the energy band and analyzed the topological phase transition law of a hexagonal star-like honeycomb PC. By changing the permittivity of the PC, the disturbance is introduced to the edge state. It is found that with the decrease of the permittivity of the PC, the gap decreases, the lower boundary state gradually redshifts, and the maximum transmittance in the straight waveguide can reach 98.8%. On this basis, a topological beam splitter was designed and analyzed. Results show that the beam splitting ratio obtained by the system is in the wide range of 0.2-3.5. Our research enriches the implementation of topological photonics, provides potential applications for topological boundary states in terahertz technology, and offers a new avenue for the design of current optical integrated devices. (c) 2024 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.
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