scholarly journals Multipole resonance and Vernier effect in compact and flexible plasmonic structures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yeonsoo Lim ◽  
Soo-Chan An ◽  
Hoon Yeub Jeong ◽  
Thi Hai-Yen Nguyen ◽  
Gangil Byun ◽  
...  
Keyword(s):  
Coupled Resonators ◽  
Low Frequencies ◽  
Resonance Amplitude ◽  
Microwave Frequencies ◽  
Transmission Amplitude ◽  
Resonance Overlap ◽  
Flexible Devices ◽  
Microwave Photonic ◽  
Plasmonic Structures ◽  
Vernier Effect

AbstractSpoof surface plasmons in corrugated metal surfaces allow tight field confinement and guiding even at low frequencies and are promising for compact microwave photonic devices. Here, we use metal-ink printing on flexible substrates to construct compact spoof plasmon resonators. We clearly observe multipole resonances in the microwave frequencies and demonstrate that they are still maintained even under significant bending. Moreover, by combining two resonators of slightly different sizes, we demonstrate spectral filtering via the Vernier effect. We selectively address a target higher-order resonance while suppressing the other modes. Finally, we investigate the index-sensing capability of printed plasmonic resonators. In the Vernier structure, we can control the resonance amplitude and frequency by adjusting a resonance overlap between two coupled resonators. The transmission amplitude can be maximized at a target refractive index, and this can provide more functionalities and increased design flexibility. The metal-ink printing of microwave photonic structures can be applied to various flexible devices. Therefore, we expect that the compact, flexible plasmonic structures demonstrated in this study may be useful for highly functional elements that can enable tight field confinement and manipulation.

Realization of Tunable Varactors Using Bi1.5Zn1.0Nb1.5O7 Thin Films

2009 ◽  
Vol 421-422 ◽  
pp. 153-156
Author(s):  
K. Sudheendran ◽  
K.C. James Raju
Keyword(s):  
Thin Films ◽  
Ground Plane ◽  
Silicon Substrates ◽  
Low Frequencies ◽  
Microwave Frequencies ◽  
Inner Radius ◽  
Voltage Dependent ◽  
Dc Bias ◽  
Fabrication And Characterization

Cubic pyrochlore bismuth zinc niobate thin films are known to exhibit voltage dependent dielectric properties. In this paper, we are demonstrating the fabrication and characterization of interdigital (IDC) and circular patch (CPC) capacitors using the pulsed laser deposited Bi1.5Zn1.0Nb1.5O7 (BZN) thin films on sapphire and platinised silicon substrates respectively. The IDCs fabricated are having 12 fingers of width 12 m each and separated by a gap of 8 m. The CPC are having circular patches with inner radius of 100 m and concentric ground plane with a radius of 300m. The electrical properties of these capacitors were characterized both at low frequencies and at microwave frequencies. The CPC varactors were having a tunability of 25% at 15 Volts. The calculated capacitance of the IDC varactor at 5.3 GHz with 0 V dc bias was 1.1 pF, which has got changed to 0.99 pF by the application of 30 Volts exhibiting a tunability of 10%.

Ultrahigh-Q microwave photonic filter with Vernier effect and wavelength conversion in a cascaded pair of active loops

2010 ◽  
Vol 35 (8) ◽  
pp. 1242 ◽  
Author(s):  
Enming Xu ◽  
Xinliang Zhang ◽  
Lina Zhou ◽  
Yu Zhang ◽  
Yuan Yu ◽  
...  
Keyword(s):  
Wavelength Conversion ◽  
Microwave Photonic ◽  
Vernier Effect

Dielectric relaxation in 2-acetylnaphthalene and related compounds

1978 ◽  
Vol 56 (4) ◽  
pp. 567-573 ◽  
Author(s):  
J. Crossley ◽  
M. A. Mazid ◽  
C. K. McLellan ◽  
P. F. Mountain ◽  
S. Walker
Keyword(s):  
Activation Parameters ◽  
Low Frequencies ◽  
Microwave Frequencies ◽  
Dielectric Absorption ◽  
Free Energy Of Activation ◽  
Polystyrene Matrix ◽  
The Matrix ◽  
Acetyl Group ◽  
Related Compounds ◽  
Xylene Solution

The dielectric absorption of 2-acetylnaphthalene and 2- and 3-acetylphenanthrene has been studied in p-xylene solution at several microwave frequencies and in a polystyrene matrix at low frequencies. Acetyl group relaxation has been established from both sets of data. A clear separation of the dielectric absorption of the molecule and the group has been achieved for both 2- and 3-acetylphenanthrene in the matrix. The Eyring activation parameters have been established for acetyl relaxation in these molecules in the matrix. The free energy of activation values for group relaxation increase in the sequence acetophenone < 2-acetylphenanthrene < 3-acetylphenanthrene < 2-acetylnaphthalene. For the p-xylene solution data the weight factor for group relaxation, C2, is appreciably lower than the theoretical value, so that C2 < C1, bearing out the findings of Fong and Smyth for 2-acetylnaphthalene. In polystyrene matrices, the data for 2- and 3-acetylphenanthrene also indicated that C2 < C1. The enthalpy of activation for acetyl relaxation in 2- and 3-acetylphenanthrene is similar to that for acetophenone and 1,4-diacetylbenzene whereas that for 2-acetylnaphthalene would seem somewhat larger.

The S-SH Confusion Test and the Effects of Frequency Lowering

2019 ◽  
Vol 62 (5) ◽  
pp. 1486-1505
Author(s):  
Joshua M. Alexander
Keyword(s):  
Cognitive Processing ◽  
Hearing Aids ◽  
Response Times ◽  
Nonlinear Frequency ◽  
Low Frequencies ◽  
Frequency Compression ◽  
Negative Side ◽  
Minimal Word ◽  
Low Pass ◽  
Negative Side Effects

PurposeFrequency lowering in hearing aids can cause listeners to perceive [s] as [ʃ]. The S-SH Confusion Test, which consists of 66 minimal word pairs spoken by 6 female talkers, was designed to help clinicians and researchers document these negative side effects. This study's purpose was to use this new test to evaluate the hypothesis that these confusions will increase to the extent that low frequencies are altered.MethodTwenty-one listeners with normal hearing were each tested on 7 conditions. Three were control conditions that were low-pass filtered at 3.3, 5.0, and 9.1 kHz. Four conditions were processed with nonlinear frequency compression (NFC): 2 had a 3.3-kHz maximum audible output frequency (MAOF), with a start frequency (SF) of 1.6 or 2.2 kHz; 2 had a 5.0-kHz MAOF, with an SF of 1.6 or 4.0 kHz. Listeners' responses were analyzed using concepts from signal detection theory. Response times were also collected as a measure of cognitive processing.ResultsOverall, [s] for [ʃ] confusions were minimal. As predicted, [ʃ] for [s] confusions increased for NFC conditions with a lower versus higher MAOF and with a lower versus higher SF. Response times for trials with correct [s] responses were shortest for the 9.1-kHz control and increased for the 5.0- and 3.3-kHz controls. NFC response times were also significantly longer as MAOF and SF decreased. The NFC condition with the highest MAOF and SF had statistically shorter response times than its control condition, indicating that, under some circumstances, NFC may ease cognitive processing.ConclusionsLarge differences in the S-SH Confusion Test across frequency-lowering conditions show that it can be used to document a major negative side effect associated with frequency lowering. Smaller but significant differences in response times for correct [s] trials indicate that NFC can help or hinder cognitive processing, depending on its settings.

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