- 标题
- 摘要
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- 实验方案
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Stress-Controlled Frequency Tuning and Parametric Amplification of the Vibrations of Coupled Nanomembranes
摘要： Noninvasive tuning of the mechanical resonance frequencies of suspended parallel nanomembranes in various monolithic arrays is achieved by piezoelectric control of their tensile stress. Parametric amplification of their thermal fluctuations is shown to be enhanced by the piezoelectric actuation and amplification factors of up to 20 dB in the sub-parametric oscillation threshold regime are observed.
关键词： nanomembrane resonators,piezoelectrical actuation,parametric excitation,stress engineering
更新于2025-09-23 15:21:01
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Filtering two-element waveguide antenna array based on solely resonators
摘要： This paper presents a design approach of a filtering antenna arrays based on the coupling matrix theory. The approach generates filtering functionality using the resonating array radiating elements and the resonator based feed network regardless to the physical structure. To implement the approach, a novel topology for a two-element array is presented, here three rectangular waveguide cavity resonators have been employed to form the filtering array. The array has a fractional bandwidth of 10% at the centre frequency 10 GHz with a reflection coefficient magnitude within the passband of 20 dB. The realised gain over the passband is 9.8 ± 0.4 dBi. The array has been fabricated and the measurements are in very good agreement with the simulations, validating the approach.
关键词： antenna array,filtering antenna array,coupling matrix,waveguide resonators
更新于2025-09-23 15:21:01
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Small mode volume plasmonic film-coupled nanostar resonators
摘要： Confining and controlling light in extreme subwavelength scales are tantalizing tasks. In this work, we report a study of individual plasmonic film-coupled nanostar resonators where polarized plasmonic optical modes are trapped in ultrasmall volumes. Individual gold nanostars, separated from a flat gold film by a thin dielectric spacer layer, exhibit a strong light confinement between the sub-10 nm volume of the nanostar’s tips and the film. Through dark field scattering measurements of many individual nanostars, a statistical observation of the scattered spectra is obtained and compared with extensive simulation data to reveal the origins of the resonant peaks. We observe that an individual nanostar on a flat gold film can result in a resonant spectrum with single, double or multiple peaks. Further, these resonant peaks are strongly polarized under white light illumination. Our simulation data revealed that the resonant spectrum of an individual film-coupled nanostar resonator is related to the symmetry of the nanostar, as well as the orientation of the nanostar relative to its placement on the gold substrate. Our results demonstrate a simple new method to create an ultrasmall mode volume and polarization sensitive plasmonic platform which could be useful for applications in sensing or enhanced light-matter interactions.
关键词： polarization,light confinement,resonators,plasmonic,film-coupled,nanostar
更新于2025-09-23 15:21:01
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High Speed Directly Modulated Fabry-Perot Lasers with an Ultra-Short Cavity Length
摘要： In this study, Fabry-Perot quantum well lasers with shortened cavity designs (25 and 50 μm) were fabricated. The devices had dry-etched and cleaved facets that exhibited an output power of up to 2.36 mW for a cavity length of 25 μm; good spectral performance was achieved. Single-optical-mode operation with better than 25dB of side mode suppression ratio can be achieved for the fabricated devices with 25- and 50-μm cavities. The short-cavity devices also exhibited high-speed modulation at elevated temperatures. Moreover, 25 Gb/s eye diagrams could be obtained at 65oC for the 25 μm device and 55oC for the 50 μm device. Due to their small area, ultra-short-cavity Fabry-Perot laser can be suitably used in next-generation light sources for optical communication.
关键词： Optical device fabrication,Semiconductor lasers,Laser cavity resonators,Amplitude modulation,Diode lasers,Quantum well lasers,Laser modes
更新于2025-09-23 15:21:01
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[IEEE 2020 IEEE 20th Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems (SiRF) - San Antonio, TX, USA (2020.1.26-2020.1.29)] 2020 IEEE 20th Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems (SiRF) - Progress Towards Fully On-Chip Frequency-Stabilization for Sub-Terahertz Sources
摘要： Resonators fabricated in heavily doped silicon have been noted to have a reduced frequency-temperature dependence compared with lightly doped silicon. The resonant frequency of silicon microelectromechanical systems (MEMS) resonators is largely governed by the material’s elastic properties, which are known to depend on doping. In this paper, a suite of different types and orientations of resonators were used to extract the ?rst- and second-order temperature dependences of the elastic constants of p-doped silicon up to 1.7e20 cm?3 and n-doped up to 6.6e19 cm?3. It is shown that these temperature-dependent elastic constants may be used in ?nite element analysis to predict the frequency-temperature dependence of similarly doped silicon resonators.
关键词： temperature dependence,Doping,resonators,silicon
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Room Temperature Wet Chemical Growth of an Oxygen Enhanced Diffusion Oxide Utilized in a Boron Diffusion Process
摘要： Resonators fabricated in heavily doped silicon have been noted to have a reduced frequency-temperature dependence compared with lightly doped silicon. The resonant frequency of silicon microelectromechanical systems (MEMS) resonators is largely governed by the material’s elastic properties, which are known to depend on doping. In this paper, a suite of different types and orientations of resonators were used to extract the ?rst- and second-order temperature dependences of the elastic constants of p-doped silicon up to 1.7e20 cm?3 and n-doped up to 6.6e19 cm?3. It is shown that these temperature-dependent elastic constants may be used in ?nite element analysis to predict the frequency-temperature dependence of similarly doped silicon resonators.
关键词： temperature dependence,Doping,resonators,silicon
更新于2025-09-23 15:21:01
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[ASME ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference - Quebec City, Quebec, Canada (Sunday 26 August 2018)] Volume 4: 23rd Design for Manufacturing and the Life Cycle Conference; 12th International Conference on Micro- and Nanosystems - Complex Logic Operations Based on MEMS Resonators
摘要： Complex logic functions based on micro electromechanical resonators has significant attention. Realization of complex logic functions through cascading micro resonators has been deterred by challenges involved in their interconnections and the large required array of resonators. This paper presents a micro electromechanical system MEMS resonator with multiple input (actuation) and output (detection) that enables the realization of complex logic operations. The devices are based on a compound resonator consisting of an in- plane clamped-guided arch beam that is mechanically coupled from its guided side to two flexure beams and to another T- shaped resonant beam. As examples, we experimentally demonstrate using the device to realize a half adder and a 1:2 DEMUX, based on electrothermal and electrostatic tuning of the arch beam and side resonant beam. The logic operation is frequency modulation. This paper demonstrates that with such compound MEMS resonators, it is possible to build more complex logic functionalities.
关键词： Multi-input and multi-output,half adder,DEMUX,electrostatic and electrothermal actuation,MEMS resonators
更新于2025-09-23 15:21:01
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PERFORMANCE IMPROVEMENT OF PATCH ANTENNA USING CIRCULAR SPLIT RING RESONATORS AND THIN WIRES EMPLOYING METAMATERIALS LENS
摘要： In this paper, the left-handed metamaterial which acts as a lens is employed to improve the performance of a microstrip patch antenna. The left-handed metamaterial used in this work is a three-dimensional periodic structure which consists of circular split ring resonators and thin wires. The three-dimensional periodic metamaterial structure shows angular independency characteristics in wide range angles, so it acts as a metamaterial lens. However, the MTM structure in?nite periodicity truncation has no impacts on the MTM lens scattering, e?ective parameters and homogeneity. The left-handed metamaterial is placed in front of the microstrip patch antenna and due to the negative refractive index property of the left-handed metamaterial; the radiated electromagnetic beam size decreases which results in a highly focused beam. The proposed antenna has been designed and simulated using CST microwave studio, and the metamaterial e?ective parameters are extracted from the S parameters by using Nicolson-Ross-Weir algorithm and by selecting the appropriate ambiguity branch parameter. Furthermore, the angular independency of the metamaterial lens has been veri?ed by rotating the metamaterial structure with respect to the excitation probe of the transverse electromagnetic waves and extracting the S-parameters and the e?ective parameters for each rotation angle. A parametric analysis has been performed to study the e?ects of the patch antenna and left-handed metamaterial lens separation and the size of the three-dimensional left-handed metamaterial structure on the radiating properties and the impedance matching of the proposed antenna. For the experimental veri?cation, the proposed antenna operating at 10 GHz is fabricated; the return loss, radiation pattern and gain for the proposed antenna with and without metamaterial are measured. Furthermore, the results show that the antenna gain is improved by 4.6 dB which validates the concept of beam focusing using negative refractive index metamaterial structure, while the return loss and bandwidth are slightly reduced. The simulation and experiment investigated the idea of the beam focusing using negative refractive index metamaterial lens in microwave regime.
关键词： microstrip patch antenna,CST microwave studio,beam focusing,Nicolson-Ross-Weir algorithm,parametric analysis,left-handed metamaterial,circular split ring resonators,negative refractive index,angular independency,experimental verification,thin wires
更新于2025-09-23 15:21:01
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Vapor Sensing with Polymer Coated Straight Optical Fiber Microtapers Based on Index Sensitive Interference Spectroscopy of Surface Stress Birefringence
摘要： Optical micro?ber tapers provide an advantageous platform for sensing in aqueous and gas environments. We study experimentally the photonic transmission in optical ?ber tapers coated with polymethyl methacrylate (PMMA), a polymeric material widely used in optical applications. We demonstrate a durable and simple humidity sensing approach incorporating tapered micro?bers attached to silicon (Si) substrate coated with active polymer layer. A model is described for the load stress effect on the birefringence giving rise to interferences in the transmission spectra, strongly dependent on the coating layer thickness, and disappearing following its slow uniform removal. The sensing approach is based on characterization of the interference patterns observed in the transmission spectra of the taper in the NIR range. The device demonstrated persistent detection capability in humid environment and a linear response followed by saturation to calibration analytes. In each analyte of interest, we de?ne principal components and observe unique calibration plot regimes in the principal component space, demonstrating vapor sensing using polymer coated microtapers.
关键词： microstructured ?bers,optical resonators,optical sensing
更新于2025-09-23 15:21:01
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Demonstration of scalable microring weight bank control for large-scale photonic integrated circuits
摘要： Microring resonators (MRRs) are reconfigurable optical elements ubiquitous in photonic integrated circuits. Owing to its high sensitivity, MRR control is very challenging, especially in large-scale optical systems. In this work, we experimentally demonstrate continuous, multi-channel control of MRR weight banks using simple calibration procedures. A record-high accuracy and precision are achieved for all the controlled MRRs with negligible inter-channel crosstalk. Our approach allows accurate transmission calibration without the need for direct access to the output of the microring weight bank and without the need to lay out electrical and optical I/Os specific for calibration purpose. These features mean that our MRR control approach can be applied to large-scale photonic integrated circuits while maintaining its accuracy with manageable cost of chip area and I/O complexity.
关键词： weight banks,Microring resonators,silicon photonics,photonic integrated circuits,optical control
更新于2025-09-23 15:21:01