- 标题
- 摘要
- 关键词
- 实验方案
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Dual-Band Frequency Selective Surface on Aperture-Coupled Patch Resonators with Different Polarization Rotation
摘要： In this letter, a dual-band frequency selective surface (FSS) based on aperture-coupled patch resonators is proposed to achieve different angles of polarization rotation, that is, 90o and 0o. The dual-band response is achieved by periodically arranging two independent sub-elements consisting of back-to-back patch resonators with coupling apertures etched on the middle metallic layer. Herein, the first passband is realized by the crossed patch resonators with a pair of rectangular apertures etched beneath the edges of the crossed patches. It can produce 180o phase difference between the two orthogonal components of a linearly polarized (LP) incident wave oriented to the diagonal of the FSS elements, thus rotating the incident polarization to its orthogonal one in this first passband. The second passband is caused by the square patch resonators with crossed apertures etched beneath the center of the square patches, thereby maintaining the incident polarization unchanged in this second passband. The operation principle is then extensively analyzed and discussed. To validate the design concept, the proposed FSS is designed, fabricated, and measured. Good agreement between the measured and simulated results is achieved to reveal the attractive dual-band and dual-polarization features of the proposed FSS.
关键词： Dual-band,aperture-coupled patch resonators,polarization rotation,frequency selective surfaces
更新于2025-09-16 10:30:52
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[IEEE 2019 International Conference on Electromagnetics in Advanced Applications (ICEAA) - Granada, Spain (2019.9.9-2019.9.13)] 2019 International Conference on Electromagnetics in Advanced Applications (ICEAA) - Design of fully-planar CSRR-based substrate integrated waveguide circuits
摘要： We present here a fully planar, low-cost and easy to fabricate power divider and a slot array antenna operating at 5G communication bands, based on a new version of the substrate integrated waveguide (SIW). The proposed SIW is synthesized by replacing each via row, with two rows of broadside-coupled complementary split ring resonators (BC-CSRRs), etched on the top and bottom metal ground surfaces of the dielectric substrate. Such resonators provide a negative effective permittivity and are capable of perfectly confining the wave within the propagating channel. The proposed waveguide exhibits excellent propagation characteristics, with losses close to those of the conventional SIW, providing a highly promising platform to implement low-cost planar components for 5G applications.
关键词： 5G,power dividers,complementary broadside-coupled split ring resonators,substrate integrated waveguide,slot antennas
更新于2025-09-12 10:27:22
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Self-starting all-fiber mode-locked laser based on Mamyshev mechanism with high-energy pulse generation at 1550 nm
摘要： An all-fiber mode-locked laser based on Mamyshev mechanism operating at 1550 nm was demonstrated. Self-phase modulation and offset spectral filtering provide high peak-power pulse selection in the laser cavity and induce mode locking. With selected operating parameters, the all-fiber mode-locked laser easily achieves mode locking without external seed pulses or auxiliary starting arms, making the laser convenient to operate. Pulses with maximum energy ~18 nJ and width 230 fs are obtained. Pulse width is almost unchanged with increasing pump power, while pulse energy increases linearly. Starting of the mode-locked laser based on Mamyshev mechanism and output spectra with different pump powers were experimentally investigated.
关键词： Fiber nonlinear optics,Fiber lasers,Laser mode locking,Laser cavity resonators
更新于2025-09-12 10:27:22
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Single coupled cavity filter design with dielectric resonators posts for millimeter‐wave applications
摘要： In this work, a single coupled cavity has presented for millimeter-wave applications. The cavity is modeled to study the effect on the quality factor by adding cylindrical posts to coupled cavity resonator. This cavity model demonstrates a higher quality factor result and better performance compare to empty substrate integrated waveguide (ESIW) filter. The concept of enhancing the quality factor by adding posts is achieved. Based on this concept, the coupled cavity and bandpass filter are presented to show the feasibility of the fabrication process for building an ESIW filter where cylindrical posts is placed in middle on the planar substrate. The introduced cavity offers very good performance around (1%) fractal bandwidth at 24.7 GHz center frequency with Q-factor of 2236. A cavity prototype is fabricated and measured where measurements agree well with simulation.
关键词： quality factor,coupled cavities,empty substrate integrated waveguide,resonators dielectric posts
更新于2025-09-12 10:27:22
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Enhanced transmitting and blocking filter design approach for laser scanning applications based on combining GSM and AFGSM methods
摘要： We present a novel and robust filter design method, developed for one-dimensional photonic crystal-based filters. Hybrid filter structures are presented comprising periodic and degenerated multilayered dielectric structures. The proposed approach provides significant flexibility in designing desired transmission band while offering widened stop-bands. In obtaining the transmission characteristics we utilize the Auxiliary Functions of Generalized Scattering Matrix Method (AFGSM), already proven to provide computational advantages in obtaining bandgap edge frequencies without solving an eigenvalue equation. With the proposed design strategy, we showcase its efficacy through designing four different filters that are utilized in laser scanning microscopy; namely a laser line filter at 800 nm wavelength for reflectance confocal microscopy, a band-pass filter at 400 nm wavelength for second harmonic generation microscopy, a laser block filter at 800 nm wavelength and a dichroic filter blocking 350-400 nm while transmitting higher wavelengths for multiphoton microscopy.
关键词： Multilayered Dielectrics,Optical Filters,Fabry-Perot Resonators,Auxiliary Functions of Generalized Scattering Matrix (AFGSM),Photonic Bandgaps (PBGs),Laser Scanning Microscopy (LSM)
更新于2025-09-12 10:27:22
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Design of a hydrogen sulfide gas sensor based on a photonic crystal cavity using graphene
摘要： We report the design and simulation of a high sensitivity H2S gas sensor using a combination of graphene properties as a hydrogen sulfide-sensitive nanomaterial and features of photonic crystal cavity. The shoulder-coupled resonant cavity is introduced in the photonic crystal that consists of a triangular array of air holes on the silicon-on-insulator substrate. To adsorb H2S gas, a graphene layer is deposited on the inner wall of the two cavity air holes. Changes in the concentration of hydrogen sulfide gas alter the refractive index of graphene, thereby resulting in wavelength shift in the sensor transmittance spectrum. We achieved a sensitivity of 1.2 ×104 nm /RIU and a detection limit of 1.87×10-6 RIU. To the best of our knowledge, the sensitivity of our sensor is much higher than other sensors previously reported in the literature.
关键词： Q factor,Cavity resonators,Sensitivity,Gas detectors,Photonic crystals,Sensors
更新于2025-09-12 10:27:22
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All-Dielectric Terahertz Plasmonic Metamaterial Absorbers and High-Sensitivity Sensing
摘要： Two types of plasmonic metamaterial absorbers (PMAs) formed from patterned all-dielectric resonators are designed and demonstrated experimentally in the terahertz (THz) range. Both PMAs use a simple grating design on highly N-doped silicon. The first shows broadband absorption with near-perfect peak absorbance at 1.45 THz and a bandwidth of 1.05 THz for 90% absorbance, while the second is a dual-band absorber. Experiments show that the second absorber has two distinct absorption peaks at 0.96 and 1.92 THz with absorption rates of 99.7 and 99.9%, respectively. A fundamental cavity mode coupled to coaxial surface plasmon polaritons is responsible for the characteristics of both PMAs. Additionally, the optically tunable responses of these all-dielectric absorbers demonstrate that the absorption behavior can be modified. The quality factor (Q) values of the dual-band resonances are 4.6 and 7.8 times larger than those of the broadband PMAs, respectively, which leads to a better sensing performance. As an example, the two proposed PMAs act as high-sensitivity sensors and demonstrate considerable potential for chlorpyrifos detection. These results show that these PMAs can be used as sensors that can detect the presence of trace pesticides in adsorption analyses, among other practical applications.
关键词： broadband absorption,all-dielectric resonators,plasmonic metamaterial absorbers,chlorpyrifos detection,dual-band absorber,terahertz,high-sensitivity sensors
更新于2025-09-12 10:27:22
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[IEEE 2019 IEEE 16th International Conference on Group IV Photonics (GFP) - Singapore, Singapore (2019.8.28-2019.8.30)] 2019 IEEE 16th International Conference on Group IV Photonics (GFP) - Coupled-Resonator-Induced-Transparency on Germanium-on-Insulator Mid-Infrared Platform
摘要： We demonstrate the operation of a thermally tunable coupled-resonator-induced transparency system on a germanium-on-insulator photonic platform working at a mid-infrared wavelength of approximately 1.95 μm. A maximum coupling rate of 1.25 GHz is realized between the two evanescently coupled microring resonators.
关键词： Mid-infrared,Germanium-on-insulator,Microring resonators,Thermo-optic tuning
更新于2025-09-12 10:27:22
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Athermalization of a self-assembled rolled-up TiO2 microtube ring resonator through incorporation of a positive thermo-optic coefficient material in planar bilayers
摘要： For the first time, this paper theoretically and experimentally investigates the thermal stability of optical filters based on self-assembled TiO2 rolled-up microtube ring resonators (RUMRs) by incorporating positive thermo-optic coefficient (TOC) materials (e.g., SiO2 and/or Si3N4). The influence of the TOC, refractive index, and thickness of the positive TOC materials on the filtering performance of the TiO2 RUMR is theoretically studied. The results illustrate that an increase in temperature leads to a blueshift in the resonant wavelength of the RUMR-based optical filter, which changes at a rate of ? 33.3 pm/K owing to the negative TOC of TiO2 (? 4.9 ± 0.5 × 10?5/K). By increasing the thickness of SiO2 or Si3N4 as a positive TOC material together with TiO2, the temperature-induced resonant shifts of TiO2/SiO2 and/or TiO2/Si3N4 RUMRs are theoretically obtained. The TIRS varies between ? 40 pm/K (? 22 pm/K) and about 30 pm/K (22 pm/K) for TiO2/SiO2 (TiO2/Si3N4) RUMRs. It is shown that thermal stability occurs when the thickness of the SiO2 (Si3N4) layer is ~ 16 nm (12 nm). At the end of this study, as a proof of concept, an experiment is demonstrated by fabricating an RUMR based on TiO2/SiO2 on the flat silicon wafer. The experimental results show that the athermalization of the system is experimentally achieved by selecting the appricated thickness ratio of TiO2/SiO2. This novel approach for athermalization of the resonators opens up interesting perspectives on the implementation of vertical and multi-routing coupling between photonic and optoelectronic layers and more specifically in a three-integration fashion.
关键词： TiO2,Rolled-up microtube ring resonators,SiO2,Athermalization,Si3N4,Thermo-optic coefficient
更新于2025-09-12 10:27:22
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Coherent Coupling of Single Molecules to Microresonators
摘要： Many interesting proposals in quantum optics and light-matter interaction rely on having multiple quantum emitters well-coupled to a single mode of light. Of particular interest are cases where several identical emitters couple to a one-dimensional (1D) photonic medium. Recently, we presented such a system by evanescent coupling of organic dye molecules to the same guided mode of an on-chip subwavelength waveguide [1]. While this coupling allowed us to demonstrate up to 7.5% transmission extinction of the propagating light by a single molecule, it is still not sufficient for achieving higher-order effects such as photon-mediated interaction of multiple emitters coupled to the same waveguide. One way to improve the waveguide-emitter coupling is the use of resonant structures, as was recently shown in our laboratory for a microscopic open Fabry-Perot cavity [2]. In that work, we demonstrated a strong Purcell broadening of the molecular emission, and almost complete extinction of the resonant cavity transmission. In the current work, we extended this approach to on-chip racetrack resonators [3], as shown in Fig. 1(a). In such a geometry, the coupling enhancement is proportional to the number of photon round trips inside the resonator, which is roughly equal to F/π, where F is the resonator finesse. Currently, our resonators can reach finesse as high as 18 when exposed to the surrounding organic matrix at cryogenic temperatures, leading to enhanced extinction dips up to 22%, as shown in the orange plot in Fig. 1(b). We additionally verify the molecule-resonator coupling by localizing the position of the molecule (marked by a white arrow in Fig. 1(a)), and by observing the expected peak in the transmission port of the resonator (blue line in Fig. 1(b)). Finally, we perform a comparison to a single waveguide on the same chip, which still showed maximal extinction of only 7%, consistent with the previous results. We discuss the observed degree of enhancement, compare it with the predictions of theoretical calculations, and evaluate future strategies for reaching on-chip near-unity coupling efficiency as well as many-emitter effects, such as light localization and generation of polaritonic states [4].
关键词： racetrack resonators,light-matter interaction,waveguide-emitter coupling,photonic medium,quantum optics,Purcell broadening,polaritonic states,resonant structures,Fabry-Perot cavity,quantum emitters
更新于2025-09-12 10:27:22