共查询到20条相似文献,搜索用时 125 毫秒
1.
提出了一种由嵌入式环谐振腔和Mach-Zehnder(M-Z)干涉仪组成的新颖带通滤波器,嵌套环是在环谐振腔的基础上,引入一个类似双线耦合环谐振器的外谐振环。依据耦合模理论推导出滤波器传递函数,并分析了环的光学长度、耦合系数和内外环长度比对其影响。模拟结果证明,通过改变结构参数,滤波器的中心波长和带宽可调,中心波长在1520nm~1600nm波段任意可调,带宽调整范围可达0.2nm~102nm。且保持输出波形有较高的平坦度和较低的旁瓣,可满足通信系统宽带及超窄带带通滤波器的设计要求。 相似文献
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通过将聚束器腔体等效为RLC并联回路,求得了功率馈入耦合环与腔体的互感及自感的公式,根据对腔体的计算结果求出了在聚束器的工作频段内达到阻抗匹配所要求的互感变化范围,并在该互感变化范围设计了可移动的耦合电感环,计算了它的自感及整个腔体的剩余电感。 相似文献
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基于微环谐振器阵列与马赫-曾德尔干涉仪的反射型滤波器性能分析 总被引:1,自引:1,他引:1
理论分析了一种将微环谐振器阵列与马赫-曾德尔干涉仪(MZI)相结合实现的反射型滤波器结构。将此结构类比为两类四端口网络级联模型,利用传输矩阵法推导出其通用函数形式,并给出单环及三环结构下的能量反射系数具体公式。通过传输函数矩阵模拟计算了取不同耦合系数值情况下的反射谱形变化,给出了原因分析及讨论。并模拟了引入传输损耗对三环结构谐振峰反射率的影响。数值结果表明:适当选取直波导与微型环以及微型环间耦合系数幅值时,此结构能够作为反射型滤波器件应用于密集波分复用(DWDM)系统,也可实现激光器反射镜面的功能;由于传输损耗增加而引起的谐振峰反射率下降程度依赖于所选取的耦合系数值。 相似文献
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自由光谱范围加倍的单微环谐振滤波器 总被引:1,自引:0,他引:1
基于两点耦合和光波干涉控制相移思想提出U型波导耦合单微环的谐振滤波器结构。利用传输矩阵法推导了此结构的数学模型,采用Matlab模拟了输出端口谱线形状。当微环与U型波导的两个耦合点之间的距离为微环周长的整数倍时,此新型微环谐振滤波器比传统的双直波导耦合单微环滤波器的自由光谱范围增加1倍。针对该结构参数,同时讨论了耦合系数对输出谱线的影响,得出当耦合系数为0.018时,输出谱线具有最佳的消光比,同时保持窄的带宽和高的品质因子。 相似文献
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《光子学报》2021,50(5)
针对氮化铝微环谐振腔实现临界耦合条件困难的问题,设计并制备了氮化铝弯曲耦合微环谐振腔。分析了微环谐振腔耦合系数公式,分别阐述了多种提高耦合强度方案的优势和劣势,最终选用弯曲耦合结构来增强耦合强度,得到了在宽耦合间隙下,实现临界耦合条件的解决方案。在蓝宝石衬底上生长了高质量的氮化铝单晶薄膜,选用导电胶克服材料的不导电性,并利用电子束曝光系统将弯曲角度为40°、耦合间隙0.19μm、波导宽度0.41μm的微环谐振腔图形化,分析优化多项氮化铝刻蚀参数,最终将图形转移至氮化铝层,得到了耦合间隙均匀、侧壁平整的弯曲耦合氮化铝微环谐振腔。该研究为氮化铝微环谐振腔实现临界耦合条件提供了选择参考。 相似文献
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提出了一种用于单纵模激光器选模的基于光纤耦合器的光纤复合环腔(CRC)滤波器的仿真方法,利用该方法对两种新型双耦合器双环CRC(DCDR-CRC)滤波器及三耦合器双环CRC(TCDR-CRC)滤波器进行了理论仿真,通过引入游标原理,分析了两种滤波器在不同环长差下的滤波特性,并通过调整DCDR-CRC及TCDR-CRC的耦合比、环长及环长差,对有效自由光谱范围(FSR)、抑制比(SR)及主透射峰带宽进行优化,计算结果表明优化后环腔的有效FSR可有效抑制波长选择器传输通带内的增益竞争,较低的SR可以抑制CRC滤波器相邻透射峰之间的增益竞争,较窄的主透射峰可以保证仅有一个激光器的纵模被选择。 相似文献
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Heinrich B Burrowes C Montoya E Kardasz B Girt E Song YY Sun Y Wu M 《Physical review letters》2011,107(6):066604
Spin injection across the ferrimagnetic insulator (YIG)/normal metal (Au) interface was studied by ferromagnetic resonance. The spin mixing conductance was determined by comparing the Gilbert damping in bare YIG films with those covered by a Au/Fe/Au structure. The Fe layer in Au/Fe/Au acted as a spin sink as displayed by an increased Gilbert damping parameter α compared to that in the bare YIG. In particular, for the 9.0 nm YIG/2.0 nm Au/4.3 nm Fe/6.1 nm Au structure, the YIG and Fe films were coupled by an interlayer exchange coupling, and the exchange coupled YIG exhibited an increased Gilbert damping compared to the bare YIG. This relationship between static and dynamic coupling provides direct evidence for spin pumping. The transfer of spin momentum across the YIG interface is surprisingly efficient with the spin mixing conductance g(↑↓) ? 1.2 × 10(14) cm(-2). 相似文献
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E. Popova N. Keller F. Jomard L. Thomas M.-C. Brianso F. Gendron M. Guyot M. Tessier 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,31(1):69-74
Magnetic exchange coupling has been observed for ultrathin films of yttrium iron garnet (Y3Fe5O12 or YIG). Single-crystalline YIG films were prepared on yttrium aluminium garnet (Y3Al5O12 or YAG) substrates by pulsed laser deposition. (111) and (110) oriented substrates were used. Film thicknesses were varied
from 180 ? to 4600 ?. Epitaxial growth of YIG on YAG was obtained in spite of the lattice mismatch of 3%. Magnetic hysteresis
loops recorded for ultrathin YIG films have a “bee-waist” shape and show a coupling between two different magnetic phases.
The first phase is magnetically soft YIG. A composition study by secondary ion mass spectroscopy shows the second phase to
be Y3Fe5-xAlxO12 due to the interdiffusion of Fe and Al at the film/substrate interface. This compound is known to be magnetically harder
and to have weaker magnetization than YIG. The coupling of the two phases leads to a hysteresis loop displacement at low temperatures.
This displacement varies differently with film thickness for two substrate orientations. Assuming an interfacial coupling,
the maximal interaction energy is estimated to be about 0.17 erg/cm2 at 5 K for (111) oriented sample.
Received 3 June 2002 / Received in final form 7 October 2002 Published online 27 January 2003
RID="a"
ID="a"Presently at LPM, Université H. Poincaré, BP 239, 54506 Vandœuvre-lès-Nancy e-mail: popova@lpm.u-nancy.fr 相似文献
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We report an experimental study on magneto-optical (MO) Kerr effects of yttrium-iron garnet (YIG) thin films incorporating Au nanoparticles. The polar MO Kerr spectra in the wavelength between 400 and 800 nm show that, by incorporating the Au nanoparticles, Kerr rotation angles become negative values in the region, where the localized surface plasmon polariton (SPP) resonance of the Au nanoparticles is located. The anomalous Kerr rotation indicates a possible coupling between the MO Kerr effect of YIG and the SPP. A mechanism for the coupling is discussed. 相似文献
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Yu. V. Khivintsev V. K. Sakharov S. L. Vysotskii Yu. A. Filimonov A. I. Stognii S. A. Nikitov 《Technical Physics》2018,63(7):1029-1035
A series of equidistant oscillations have been revealed in the transmission spectrum and dispersion law of Damon–Eshbach surface magnetostatic waves (SMSWs) propagating in submicron (200-nm) yttrium–iron garnet (YIG) films manufactured by means of ion-beam sputtering onto gadolinium–gallium garnet (GGG) substrates. These oscillations correspond to the excitation of magnetoelastic waves in the YIG–GGG structure at frequencies of resonant interaction between the surface magnetostatic waves and the elastic shear modes of the wave-guiding YIG–GGG structure. The obtained results show that the studied YIG films are characterized by an efficient magnetoelastic coupling between their spin and elastic subsystems and the matching of acoustic impedances at the YIG–GGG interface, thus providing the possibility to consider the ion-beam sputtering of YIG films onto GGG substrates as a promising technology for the creation of magnonic and straintronic devices. 相似文献
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本文阐述了n≈k的超薄金属膜与介质膜组成周期对称膜系的光学特性,并结合Ag、Al等膜层的高反特性提出了可见光区诱导窄带高反膜系结构,推导出膜系的反射率、反射峰值、反射半波带宽等光谱反射特性的近似公式,实验证实了理论设计和分析.同时也提出了设计红外和紫外窄带高反滤光片的方法. 相似文献
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Yasuyuki Okamura Masayuki Chatani Tetsuya Kikuchi Sadahiko Yamamoto 《Optical and Quantum Electronics》1985,17(6):427-430
This paper describes the experimental results on the orthogonally polarized mode conversion in a YIG rib channel waveguide, in which a small magnetic field induced around the electrode deposited on the waveguide was used. The dependence of mode conversion efficiency on the coupling length and the effect of a d.c. bias field applied to the waveguide were investigated. The Faraday rotation angle of the fabricated YIG rib channel waveguide was found to be 160° cm–1, which was a reasonable value compared with that in the YIG planar waveguide reported previously. Furthermore, an increase in conversion efficiency and a decrease in switching time were found in the presence of a d.c. magnetic bias field. 相似文献
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Tao Yang Xiao Bo Yang Ren Hou Liu En Li Tie Hua Wang Mong Lin Zheng 《International Journal of Infrared and Millimeter Waves》2001,22(2):343-349
In this paper, a new method to realize pre-selected harmonic mixer is introduced. It includes a harmonic mixer, and a YIG turning filter (YTF) design. A digital driver is used for YTF, which can realize linearization modification and temperature compensation. The spectrum analyzer's out scanning voltage is given an A/D conversion and interface to digital driver. 相似文献
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Ming-En Tian 《中国物理 B》2022,31(7):78401-078401
A triple-channel bandpass filter with switchable and tunable functions is proposed, which is based on a triple-mode cross resonator. The varactors and switching diodes are loaded at the end of the resonator. Because of the use of switches, resonators have four working states: conventional single-mode, two dual-modes, and one triple-mode. The varactor makes the channel independently adjustable. Finally, a triple-channel bandpass filter with switchable and tunable functions is designed by using two identical triple-mode resonator coupling structures. To solve the problem of whether each channel in the multi-channel filter is independently adjustable, this paper gives a simple and rigorous judgment method, namely rank criterion, which is a necessary and sufficient condition for each channel to be independently adjustable. The method of designing an element variable coupling matrix (EVCM) is adopted, which can not only obtain the desired frequency response through adjustable elements but also help to select resonators and coupling modes in the actual circuit design. The final circuit size of the designed filter is 0.29 λg×0.26 λg. The measured results are in good agreement with the simulation results. 相似文献
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通过耦合三维微波腔中光子和腔内钇铁石榴石单晶小球中的自旋波量子形成腔-自旋波量子的耦合系统,并通过精确调节系统参数在该实验系统中观测到各向异性奇异点.奇异点对应于非厄米系统中一种特殊状态,在奇异点处,耦合系统的本征值和本征矢均简并,并且往往伴随着非平庸的物理性质.以往大量研究主要集中在各向同性奇异点的范畴,它的特征是在系统参数空间中沿着不同参数坐标趋近该奇异点时具有相同的函数关系.在这篇文章中,主要介绍实验上在腔光子-自旋波量子耦合系统中通过调节系统的耦合强度和腔的耗散衰减系数两条趋近奇异点的路径而实现了各向异性奇异点,具体分别对应于在趋近奇异点时,本征值的虚部的变化与耦合强度和腔的衰减系数的变化会有线性和平方根不同的行为.各向异性奇异点的实现有助于基于腔光子-自旋波量子耦合系统的量子信息处理和精密探测器件的进一步研究. 相似文献