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41.
M. N. Kotov V. F. Masterov V. V. Potapov A. V. Prichodko O. V. Smertin N. M. Shybanova 《International Journal of Infrared and Millimeter Waves》1993,14(8):1679-1687
Experimental investigations of superconductivity effects in single-phase and multiphase Bi2Sr2CaCu2O8 single-crystals have been carried out at 142 GHz frequency by means of the standing wave profile method [1]. Josephson harmonic generation has been observed to be responsible for the appearence of additional peaks on the standing wave profile of the open dielectric resonator loaded with a properly orientated multiphase high-Tc superconductor specimen. This leads to the conclusion that most of the Josephson junctions in multiphase crystals are located in certain crystallographic planes. The investigations of temperature dependencies showed that sharp resonant peaks of conductivity observed earlier [2] at 60 GHz could also be observed at 142 GHz. 相似文献
42.
This paper investigates the performance of a quasioptical gyrotron, when the electron beam interacts with the radiation fields at harmonics of the gyrofrequency. The nonlinear equations of motion are obtained in the slow-timescale. The expression for the linear gain is derived and the conditions for excitation are given (frequency threshold, optimal operating point, bean current and resonator quality thresholds). In the nonlinear regime, it is shown that maximum efficiencies comparable to those at the fundemental (50%) are possible, albeit at a prohitively high radiation field amplitude, while realistically feasible field amplitudes can give somewhat smaller, but nevertheless still high efficiencies (15%). Finally, the results are suplemented by empirical scaling laws, useful for experimental designs. 相似文献
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44.
A 10-MHz face shear (FS) square micromechanical resonator based on silicon-on-insulator (SOI) technology is presented in this paper. In order to examine the improvement of quality factor as well as motional resistance Rx in this structure, the center-stem anchor is employed in this study. The benefit of anchoring the square in the center, which is the nodal point, is that the energy losses through the anchor can be minimized. Hence, a quality factor value of 2.0 million and the motional resistance of 8.2 kΩ can be obtained with an FS mode resonator via finite element (FE) simulation. The results show the significance of the FS mode in this design, not only in its structure but also in its square-extensional mode and Lame-mode. Additionally, an SOI-based fabrication process is proposed to support the design. 相似文献
45.
提出由T型空腔和挡板组成的两种金属-电介质-金属(MIM)波导结构,分别为:正T型空腔结构和倒T型空腔结构,并应用有限元法系统地研究了该结构的透射特性.对于正T型空腔结构,仿真结果出现了双重法诺共振现象,并且共振波长可以通过改变T型空腔长度和高度进行调节.该结构有助于设计成敏感度达到1 620nm/RIU、品质因数为5.4×10~4的纳米传感器.对于倒置T型空腔,在波导中产生了多重法诺共振现象,其敏感度可达1 560nm/RIU,品质因数为9.37×104.该结构有望在光学集成回路,特别是纳米传感器、光束分路器方面具有广泛应用. 相似文献
46.
By taking the coupling effect into consideration, we study the resonance condition of a photonic wire microring resonator (PWRR) sensor and compare our results with the previous work. Simulation results show that the resonant wavelength and sensitivity strongly depend on the coupling strength. The difference caused by the coupling effect can be up to tens of nanometers for the resonant peak position and tens of nm/RIU for the sensitivity in a silicon-on-insulator (SOI) PWRR. Such a giant influence from coupling effect cannot be disregarded and should be considered seriously for the design and application of PWRRs. It also shows an alternative tuning technique by controlling the coupling strength. 相似文献
47.
《Current Applied Physics》2019,19(9):984-986
A highly symmetric ZnO micro-fence is prepared to form an optical resonator, which a symmetric array consisting of six elongated hexagonal microcolumns. It is found that the luminescence emission could be enhanced at the edge of ZnO micro-fence and the wavelength dependent light intensity could be influenced by its geometry. The optical characterization along with theoretical calculations and computer simulation analysis suggest that the Fabry-Perot and Cross-whispering gallery modes are generated in ZnO micro-fence. The individual ZnO micro-fence can regarded as an optical resonator structure. Furthermore, it is proposed that the source concentration around the substrate during the growth is a crucial factor for forming such a micro-fence. 相似文献
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A 2D hole‐type hexagonal lattice photonic crystal is utilized, herein, to detect the refractive index change of the material infiltrated into the designed circular sensing area which also resembles a ring resonator. The accuracy of the detection process is enhanced considering the simultaneous shift of the resonance wavelengths and the intensity modulation which occur in two separate spectral regions. The presented structure has the ability to detect liquids, material concentrations in fluids and gases having refractive indices in the range of n = 1–2 with sensitivity and quality factor of 61 nm/RIU and 3000, respectively, for resonance‐wavelength‐shift‐based operation. The detection range of n = 1–1.4 with the sensitivity of S = 0.69 NI/RIU is achieved for the intensity‐based measurement and the results show good linearity in the operating range. 相似文献
50.
Ming-En Tian 《中国物理 B》2021,30(5):58503-058503
A single-stage ring resonator capable of introducing six modes within the ultra-wideband (UWB) passband is presented. The sextuple-mode resonator consists of three rings and three sets of stepped-impedance open stubs. Based on this sextuple-mode resonator, a UWB filter fed by the interdigital-coupling line (ICL) is designed. And we propose a two-round interpolation method to obtain the filter's initial dimensions. The designed filter is fabricated on a double-sided YBCO/MgO/YBCO high-temperature superconducting (HTS) thin film for demonstration. The experimental results show that this UWB filter produces eight resonances in the passband eventually, which effectively improves the in-band reflection and the band-edge steepness. Moreover, the upper stopband performance is enhanced due to the transmission zeros (TZs) generated by the stepped-impedance open stubs and the ICL structure. The measured good performance verifies the practicability of the two-round interpolation approach, which can also be extended to other odd-even-mode filter designs. 相似文献