Compact Resonator Research Articles

A Bayesian neural network predicts the dissolution of compact planetary systems

We introduce a Bayesian neural network model that can accurately predict not only if, but also when a compact planetary system with three or more planets will go unstable. Our model, trained directly from short N-body time series of raw orbital elements, is more than two orders of magnitude more accurate at predicting instability times than analytical estimators, while also reducing the bias of existing machine learning algorithms by nearly a factor of three. Despite being trained on compact resonant and near-resonant three-planet configurations, the model demonstrates robust generalization to both nonresonant and higher multiplicity configurations, in the latter case outperforming models fit to that specific set of integrations. The model computes instability estimates up to [Formula: see text] times faster than a numerical integrator, and unlike previous efforts provides confidence intervals on its predictions. Our inference model is publicly available in the SPOCK (https://github.com/dtamayo/spock) package, with training code open sourced (https://github.com/MilesCranmer/bnn_chaos_model).

Implementation of polarization rotation using microring resonator and its application to design all-optical switch

A compact microring resonator (MRR) and its implementation for polarization rotation-based all-optical switching are proposed. The polarization rotation has been achieved by enhancing geometry-induced birefringence of the device and with the insertion of polarization rotator in the race-track-shaped MRR. The proposed device has been modeled using Jones matrix and the finite-difference time-domain simulation method. The insertion loss and the extinction ratio have been found to be −0.13 and 19.39 dB, respectively.

Low power, high speed, all-optical logic gates based on optical bistability in graphene-containing compact microdisk resonators

CMOS-compatible all-optical logic gates based on optical bistability are designed and numerically characterized. For this, graphene and H-BN-based hybrid plasmonic microdisk/waveguide structures have been used to achieve optical bistability at very low threshold power and with small dimensions. The simulation results and coupled-mode theory calculations show that, by adjusting the radius of the microdisk resonator, the threshold power and response time of the optical bistability can be tuned in a wide range. It is shown that bistable devices with overall dimensions of 2µm×2.2µm can easily be designed having either threshold powers as low as 0.79 µW (microdisk radius of 0.92 µm) or very short fall time and rise times of 1.24 and 1.53 ps (microdisk radius of 0.93 µm). The design procedure for the AND, NAND, OR, NOR, and NOT logic gates is discussed. Simulation results show that the proposed logic gates have much smaller footprints, lower power consumption, and higher speeds with acceptable response time, compared with the previously reported structures.

Active Q-switching operation of a Tm:SrF2 single crystal fiber laser near 2 µm

Single crystal fiber (SCF) lasers have attracted extensive attention recently. In this paper, Tm:SrF2 SCF was successfully grown by the temperature gradient method. With a compact resonator, the acousto-optically Q-switched properties of a diode-pumped Tm:SrF2 SCF laser was investigated first. At the repetition rate of 500 Hz, a highest pulse energy of 1.32 mJ and a narrowest pulse width of 51 ns were acquired with the absorbed pump power of 2.60 W, resulting in the peak power of 25.85 kW. These results indicate that Tm:SrF2 SCF is a promising laser gain material for generating ∼2 µm region pulsed lasers.

Design of Compact Coupled Resonators for Triple-Band Wireless Power Transfer

This letter suggests a design methodology for triple-band wireless power transfer (TB-WPT) filters. The proposed triple-bandpass filter (TB-PF) is designed using two complementary split-ring resonators CSRR-DGSs coupled in a back-to-back configuration, and operates at 0.6, 2.4, and 2.7 GHz. Each of the transmitter and the receiver has a size of 25 mm × 25 mm. The measured power transfer efficiencies were 96% for 0.6 GHz, 74% at 2.4 GHz, and 70% at 2.7 GHz, respectively, at a separation distance between the transmitter and receiver of 10 mm.

High-efficiency compact SRR–CSRR–SIW antenna based on CRLH-TL

A high-efficiency compact split-ring resonator (SRR)–complimentary split-ring resonator (CSRR)–substrate integrated waveguide (SIW) rectangular resonator antenna based on a composite right/left-handed transmission line is presented in this paper. A four-element rectangular CSRR structure is etched on the front of the antenna, and a four-element rectangular SRR structure is loaded on the back of the metal to correspond with each other, thus forming a composite right/left-handed transmission line structure. By meandering technique, a rectangular CSRR is etched on the front of the metal surface to reduce the frequency and realize the miniaturization of the antenna. Combined with SIW rectangular resonator, the high-efficiency compact antenna is finally realized. Simulation and experimental results show that the −10 dB impedance bandwidth of the SRR–CSRR–SIW rectangular resonator antenna is 5.26∼5.29 GHz (1.14%) and 9.07∼9.15 GHz (0.88%). The resonance frequency is 5.26 and 9.11 GHz. The gains are 5.33 and 5.25 dBi. The antenna can be widely used in WLAN and WiMAX.

Sub‐nanosecond, single longitudinal mode laser based on a VBG‐coupled EOQ Nd:YVO4 oscillator for remote sensing

AbstractHigh energy, sub‐nanosecond, single longitudinal mode (SLM) pulse is especially preferred for LiDAR application. In this paper, a kHz‐level sub‐nanosecond electro‐optical Q‐switched Nd:YVO4 laser of SLM operation for remote sensing was demonstrated. By utilizing a compact resonator with a Volume Bragg Grating as output coupler, maximum SLM output power of 1.08 W and pulse width of 919 ps was obtained at 10 kHz. Moreover, we proposed a theoretical model to calculate the multimode threshold of the VBG‐coupled cavity. The longitudinal mode characteristics at four different cavity lengths were investigated experimentally and the results match well with the numerical simulations, which validates the theory. We expected the method could help to guide VBG‐coupled cavity design and construction.

A compact photonic resonator absorption microscope for point of care digital resolution nucleic acid molecular diagnostics.

Rapid, sensitive, and selective detection of nucleic acid biomarkers for health diagnostic applications becomes feasible for point of care scenarios when the detection instrument is inexpensive, simple, and robust. Here, we report the design, implementation, and characterization of a point of care instrument for photonic resonator absorption microscopy (PRAM) that takes advantage of resonant optical coupling between plasmonic gold nanoparticle tags and a photonic crystal (PC) surface. Matching the PC resonant wavelength to the gold nanoparticle's surface plasmon wavelength generates localized and efficient quenching of the PC resonant reflection intensity, resulting in the ability to clearly detect and count individual gold nanoparticles when they are captured on the PC surface. Surface-captured nanoparticles are observed by illuminating the PC at normal incidence with polarized light from a low-intensity red LED, and recording of PC reflected intensity on an inexpensive CMOS image sensor. A contrast limited adaptive histogram equalization (CLAHE) image processing algorithm was applied to derive counts of captured nanoparticles. The instrument is utilized in the context of an activate capture + digital counting (AC + DC) assay for a specific miRNA sequence, using nucleic acid toehold probes applied to gold nano-urchin (AuNU) nanoparticles to achieve 160 aM detection limits in a 30 min. assay.

Compact T-complementary split-ring resonator antenna and antenna array

A compact T-complementary split-ring resonator (CSRR) antenna was developed. Different from traditional designs, the proposed CSRR functioned not only as a loading structure but also as a radiator. The operation of the T-CSRR antenna was similar to that of a slot antenna with a gain of 3.1 dBi. Because of the loading effect of the CSRR, the size of the radiator of the proposed antenna was only 0.14λ 0 × 0.26λ 0. The circuit sizes of the proposed T-CSRR antenna were 50% and 74% smaller than those of the traditional half-wavelength slot and T-shaped monopole antennas, respectively. For further gain enhancement, the performance of two feasible array arrangements, namely collinear and parallel arrays with 1 × 4 T-CSRR elements, were compared, which revealed that the parallel 1 × 4 T-CSRR antenna array can achieve a gain of 9 dBi at 2.45 GHz.

Compact MIM plasmonic ring resonator for nano-interconnect applications

Abstract In this article, a compact plasmonic metal-insulator-metal ring resonator has been proposed and investigated. The proposed waveguide structure can be turned into a Plasmonic optical filter through alteration in various parameters of the structure geometry, such as radius of ring resonator, width of the waveguide channel, dielectric constant of insulating material and the shifting of the output channel. It is observed that the transmission peaks exhibit redshift with increased radius of the ring resonator and decreased channel width. Several metals have been successfully trialed, in which the silver metal shows high response with near 90% transmission. For the first time, three transmission peaks have been observed in the near infrared regime with air cavity over a wide range of bandwidth, which makes it strong candidate for the significant nano-interconnect and sensing applications.

An ultra-wideband rectangular ring dielectric resonator antenna integrated with hybrid shaped patch for wireless applications

Abstract A new wideband omni-directional compact rectangular ring dielectric resonator antenna (RRDRA) fused with slotted bevel shaped patch antenna is presented for the ultra-wideband (UWB) applications. The RRDR (rectangular ring dielectric resonator) is employed to generate lower order radiating modes with merge with the modes of patch to obtain high impedance bandwidth in UWB region. Further, RRDR use led to reduction in overall conductor loss to achieve high radiation efficiency. The proposed RRDRA structure achieved an impedance bandwidth covering the frequency range from 2.6–15.6 GHz, or ∼142%. The measured results show that the proposed DRA provides peak measured gain of 6.2 dBi and radiation efficiency of 90% at resonant frequency 6.3 GHz with stable omni-directional monopole like radiation patterns with low cross-polarization. The proposed antenna has a short ground plane of size 40 × 40 × 11.6 mm3 or ∼0.34λ 0 × 0.34λ 0 × 0.10λ 0 at 2.6 GHz.

Design and performance of four port MIMO antenna for IOT applications

In this paper, a four port MIMO antenna of compact split ring resonator (SRR) type with high degree of isolation among four ports on the antenna has been proposed for MIMO multiband applications. It is Tribands which operate at frequencies 1.44 GHz (−11 dB), 2.3GHz(−10 dB) and 4.2 GHz (−245 dB) respectively. This proposed MIMO antenna is designed with meander line for better gain and Split Ring Resonator (SRR) in the form of ring for high isolation between the antenna elements. A loaded stub is used to achieve the resonant frequency. The proposed MIMO antenna was simulated with IE3D EM software by Mentor graphics and the features such as impedance view, lower return loss, gain, radiation pattern and VSWR, etc are measured. The proposed antenna has better gain and provides higher isolation between multiple antenna elements.

Compact tunable YIG-based RF resonators

We report on the design, fabrication, and characterization of compact tunable yttrium iron garnet (YIG)-based RF resonators based on μm-sized spin-wave cavities. Inductive antennas with both ladder and meander configurations were used as transducers between spin waves and RF signals. The excitation of ferromagnetic resonance and standing spin waves in the YIG cavities led to sharp resonances with quality factors up to 350. The observed spectra were in excellent agreement with a model based on the spin-wave dispersion relations in YIG, showing a high magnetic field tunability of about 29 MHz/mT.

A compact hybrid dielectric resonator antenna for multiband in wireless applications

This article exhibits the composite dielectric resonator antenna (DRA) for ISM band, Wi-Max and WLAN applications. The proposed DRA is aiming for speech signal and video transmission in the range of wi-max/WLAN. DRA’s are used in many digital signal processing applications because they are capable of locating signal sources. Microstrip feed line excites the exhibited structure. A circular dielectric resonator antenna with circular ring and cross shaped strip is designed to generate tri-band characteristics. The proposed antenna structure cover three different frequency bands, i.e. 1.85–2.5 GHz, 2.97–3.92 GHz and 4.821–5.9 GHz, with the fractional bandwidth of 30.1%, 27.5% and 20.9% respectively. An ISM band, Wi-max as well as WLAN are being utilized for correspondence of continuous traffic including speech signal, video and information to supervise medical issues in wireless body area networks (WBAN) advancement. To strengthen the resonator appearance as well as miniaturize the volume, the customized circular metallic component and cross shaped strip are stacked onto the substrate. The simulated results are verified by using fabricated antenna and the results are compared. The proposed model is strongly encouraging the wireless applications.

Wideband-Narrowband Switchable Tapered Slot Antenna for Breast Cancer Diagnosis and Treatment

In this paper, a wideband-narrowband switchable tapered slot antenna (TSA) with a compact meander line resonator for an integrated microwave imaging and hyperthermia system was proposed. A compact meander line resonator, which exhibited band-pass characteristics and provided narrowband characteristics by using one PIN diode, was fabricated beneath the tapered slot of the wideband TSA to minimize the degradation of the wideband characteristics. Moreover, the electromagnetic energy was transferred to the meander line resonator with a coupling effect to ensure effective frequency switching. By adapting a PIN diode on the meander line resonator, frequency switching could be achieved. In this way, the proposed antenna could operate in a real-time frequency switching mode between the ultra-wideband (UWB; 3.1~10 GHz), which is used for microwave imaging, and the 2.45 GHz band (industrial, scientific, and medical, ISM band), which is used for microwave hyperthermia. Frequency and time-domain results proved the applicability of the proposed antenna to an integrated breast cancer detection and treatment system.

Resonant bistable 2 × 2 crossbar switches using dual nanobeams clad with phase-change material

We present the first bistable 2 × 2 crossbar switches using dual suspended nanobeams with phase changing Ge2Sb2Se4Te1 (GSST) cladding material. The dual suspended nanobeam configuration gives a higher-temperature pulse that will efficiently change the phase of a nanoscale GSST cladding on each nanobeam cavity region. The compact resonant 2 × 2 Mach–Zehnder switch has stable cross and bar states corresponding to the amorphous and crystalline phases of the GSST, respectively. We have optimized the nanobeam design using 3D FDTD and have made detailed numerical simulations that predict low insertion loss and low crosstalk with ∼100 GHz bandwidth. Finally, the application of this device to N x N x Mλ wavelength cross-connect switching is presented. The unique integration of switch design elements presented in this paper enables, for the first time, the combination of nonvolatile resonant behavior, low switching power, low insertion loss and crosstalk, wide bandwidth, and fast switching times, for WDM switching applications.

Topological guided-mode resonances at non-Hermitian nanophotonic interfaces

Abstract The topological properties of photonic microstructures are of great interest because of their experimental feasibility for fundamental study and potential applications. Here, we show that robust guided-mode-resonance states exist in photonic domain-wall structures whenever the complex photonic band structures involve certain topological correlations in general. Using the non-Hermitian photonic analogy of the one-dimensional Dirac equation, we derive essential conditions for photonic Jackiw-Rebbi-state resonances taking advantage of unique spatial confinement and spot-like spectral features which are remarkably robust against random parametric errors. Therefore, the proposed resonance configuration potentially provides a powerful method to create compact and stable photonic resonators for various applications in practice.

Analysis of whispering gallery modes resonators: wave propagation and energy balance models

Electromagnetic whispering gallery modes (WGM) are surface waves guided by the curvature of an interface. Microspheres, microdisks and microcylinders –as for example standard optical fibers– are high quality microresonators for the WGM. In fact, they can be regarded as compact and small ring resonators. Here, we present a comparison between wave propagation and energy balance models, stablishing the equivalence and discussing the basic characteristics of these two complementary approaches.

Compact symmetrical slot coupled linearly polarized two/four/eight element MIMO bowtie DRA for WLAN applications

This paper presents a compact and low cost MIMO (Multiple-Input-Multiple-Output) Bowtie dielectric resonator antennas for two, four and eight elements for public safety entities (4.94–4.99 GHz) and indoor WLAN (5.15–5.35 GHz) applications. The fractional impedance bandwidth (4.72 GHz – 5.44 GHz) is 14.17% for all ports and strengthens the targeted frequency range gain. Two bubbled I-shape embedded inside the rectangular box defective ground structure to enhance the separation between ports by etching therefore over the operating frequency band, isolation between ports exceeds 25 dB and maximum ECC (envelope correlation coefficient) of 0.04. The designed compact unit cell antenna has a dimension of 30 × 25.6 mm2 (i.e. 0.5λ0 × 0.4 λ0 where λ0 is calculated at 5.2 GHz in the free space) and finally proposed 8-element antenna having a size of only 120 × 51.2 mm2 (2.07 λ0 × 0.88 λ0). Within their finest values, MIMO diversity performance parameters are obtained. The gain of the antenna unit cell, two, four and eight elements are 5.24 dBi, 5.49 dBi, 5.68 dBi and 6.2 dBi respectively and these gain values are most suitable for WLAN applications. To show the simulated performance, a prototype of all radiators would be manufactured and tested experimentally and measured results are good agreement with simulation result.

Fano-like resonances in nanostructured thin films for spatial filtering

Fano-like resonant coupling of electromagnetic radiation with planar waveguiding modes of nanostructured thin films is proposed and realized experimentally. Different from conventional Fano coupling to compact resonators with the discrete spectrum, we report Fano-like coupling to infinitely extended planar waveguiding modes of the spatially unbound system. We fabricated the films by the ion beam sputtering method on nano-modulated substrates. The observed Fano-like process shows extremely strong sensitivity with respect to the wavelength and especially to the incidence angle of the radiation and can potentially be used for frequency and spatial filtering of light in transmission/reflection through/from such nanostructured thin films.