本文選題：表面等離子體　切入點(diǎn)：金屬-絕緣體-金屬波導(dǎo)　出處：《湖南大學(xué)》2014年碩士論文

【摘要】：表面等離激元(SPPs),亦稱表面等離子體,是入射光子與金屬表面自由電子相互作用形成的非輻射電磁模式,是沿著金屬-介質(zhì)界面?zhèn)鞑サ南挪?在納米量級(jí)上具有顯著的局域增強(qiáng)效應(yīng)。利用表面等離子體的這一特殊性質(zhì),可以實(shí)現(xiàn)亞波長(zhǎng)量級(jí)上的電磁波傳輸與調(diào)控�；诒砻娴入x子體的納米光子器件是實(shí)現(xiàn)納米全光網(wǎng)絡(luò)的基礎(chǔ),因此如何實(shí)對(duì)現(xiàn)納米尺寸上表面等離子體的有效調(diào)控成為該領(lǐng)域研究者關(guān)注的熱點(diǎn)。其中表面等離子體金屬-絕緣體-金屬(MIM)波導(dǎo)避免了輻射模和泄漏模的出現(xiàn),可以將電磁波有效地局域在亞波長(zhǎng)結(jié)構(gòu)內(nèi),從而實(shí)現(xiàn)電磁波在納米尺度上的傳輸。近幾年來,基于MIM波導(dǎo)的功能器件已被設(shè)計(jì),如光分束器、定向耦合器、布拉格反射器、濾波器等,研究者通過調(diào)節(jié)其結(jié)構(gòu)參數(shù)來實(shí)現(xiàn)對(duì)其性能的調(diào)節(jié)。本論文中采用時(shí)域有限差分方法,針對(duì)MIM波導(dǎo)結(jié)構(gòu)中表面等離子體在紅光到近紅外波段的傳輸特性進(jìn)行了研究,并設(shè)計(jì)了幾種基于MIM波導(dǎo)的諧振腔結(jié)構(gòu)。主要工作內(nèi)容以及結(jié)果如下： 提出了一種新型基于MIM波導(dǎo)的諧振腔結(jié)構(gòu),該結(jié)構(gòu)由兩個(gè)波導(dǎo)通道與個(gè)內(nèi)嵌金屬條的圓盤組成。重點(diǎn)研究?jī)?nèi)嵌金屬條幾何尺寸及其旋轉(zhuǎn)角度對(duì)該結(jié)構(gòu)傳輸性能的影響。研究發(fā)現(xiàn),當(dāng)金屬條寬度為幾十納米時(shí)該結(jié)構(gòu)呈現(xiàn)帶通濾波的性能,調(diào)節(jié)金屬條的高度可以改變?yōu)V波波長(zhǎng),該結(jié)構(gòu)會(huì)起到可調(diào)濾波的效果。當(dāng)旋轉(zhuǎn)該金屬條,出現(xiàn)了一個(gè)新的諧振模式；旋轉(zhuǎn)角度的大小不僅對(duì)濾波波長(zhǎng)有影響,而且能夠有效控制諧振強(qiáng)度。當(dāng)金屬條尺寸較大,寬度和高度均兩百多納米時(shí),該結(jié)構(gòu)可以讓較寬波段的電磁波通過,此時(shí)的透射譜與九十度拐角波導(dǎo)的透射譜類似。 提出了由兩個(gè)MIM波導(dǎo)通道與一個(gè)內(nèi)嵌金屬條方形諧振腔組成的復(fù)合型結(jié)構(gòu)。重點(diǎn)研究金屬條幾何尺寸對(duì)該結(jié)構(gòu)傳輸性能的影響,并與上述內(nèi)嵌金屬條圓盤諧振腔結(jié)構(gòu)的性能進(jìn)行了對(duì)比,發(fā)現(xiàn)兩種結(jié)構(gòu)在功能上非常相似。當(dāng)金屬條寬度為幾十納米時(shí)該結(jié)構(gòu)呈現(xiàn)帶通濾波的性能,調(diào)節(jié)金屬條的高度可以改變?yōu)V波波長(zhǎng)。旋轉(zhuǎn)該金屬條,透射譜上出現(xiàn)兩個(gè)透射峰,即諧振腔內(nèi)有兩種諧振模式,通過調(diào)節(jié)金屬條旋轉(zhuǎn)角度不僅能對(duì)兩種模式下的濾波波長(zhǎng)進(jìn)行微調(diào),還能夠有效調(diào)整這兩種模式的諧振強(qiáng)度。當(dāng)金屬條尺寸較大,寬度和高度均兩百多納米時(shí),該結(jié)構(gòu)可以讓研究波段所有的電磁波都高效通過,相當(dāng)于中間的內(nèi)嵌金屬條方形諧振腔不存在。 提出了基于MIM波導(dǎo)的缺陷諧振環(huán)結(jié)構(gòu)。重點(diǎn)研究缺陷的幾何尺寸及位置對(duì)其傳輸特性的影響。模擬計(jì)算其透射譜及共振模式下的磁場(chǎng)分布,并與傳輸線模型的計(jì)算結(jié)果進(jìn)行比較,以明確該結(jié)構(gòu)的傳輸特性。結(jié)果表明,當(dāng)設(shè)置缺陷時(shí),破壞了環(huán)腔結(jié)構(gòu)原有的對(duì)稱性,影響原有的幾種共振模式,從而出現(xiàn)了新穎的濾波特性；發(fā)現(xiàn)其濾波特性依賴于缺陷的尺寸大小,通過改變?nèi)毕莩叽缈梢杂行д{(diào)節(jié)濾波波長(zhǎng),并且當(dāng)缺陷尺寸設(shè)定為特定值時(shí),有些模式間發(fā)生簡(jiǎn)并,提高結(jié)構(gòu)濾波性能。此外,缺陷諧振環(huán)結(jié)構(gòu)的部分諧振模式依賴于缺陷的位置,當(dāng)缺陷位置不同時(shí),通道波導(dǎo)與缺陷諧振環(huán)之間的耦合強(qiáng)度不同,對(duì)不同諧振波長(zhǎng)下的透射率有一定的影響。此結(jié)構(gòu)在不改變結(jié)構(gòu)總尺寸的情況下,可調(diào)節(jié)濾波波長(zhǎng),實(shí)現(xiàn)了更寬頻段的濾波,并有效調(diào)節(jié)其透射率。
[Abstract]:Surface plasmon polariton ( SPPs ) , also known as surface plasmons , is a non - radiative electromagnetic mode formed by free electron interaction between incident photons and metal surfaces .

A novel resonant cavity structure based on MIM waveguide is proposed . The structure is composed of two waveguide channels and a circular disk with embedded metal strips . The influence of the geometry size of embedded metal strip and its rotation angle on the transmission performance of the structure is studied . It is found that when the width of the metal strip is tens of nanometers , the structure exhibits band - pass filtering performance , and the height of the metal strip can change the filtering wavelength .
when the size of the metal strip is larger , the width and the height are both more than two hundred nanometers , the structure can let the electromagnetic wave of the wider wave band pass through , and the transmission spectrum of the transmission spectrum is similar to the transmission spectrum of the ninety - degree corner waveguide .

A composite structure consisting of two MIM waveguide channels and an embedded metal strip square resonant cavity is proposed . The influence of the geometry size of the metal strip on the transmission performance of the structure is studied , and compared with the performance of the embedded metal strip disk resonator structure , the structure presents band - pass filtering performance , the height of the metal strip can be adjusted to change the filter wavelength .

In this paper , the structure of defect resonant ring based on MIM waveguide is presented . The influence of geometry size and location on the transmission characteristics of MIM waveguide is studied . The distribution of magnetic field in the transmission spectrum and resonance mode is simulated . The transmission characteristics of the structure are determined . The results show that the original symmetry of the ring cavity structure is destroyed when the defect is set , and the original resonance modes are affected , so that the novel filter characteristic appears ;
In addition , the partial resonance mode of the defect resonant ring structure is dependent on the position of the defect , and when the defect position is different , the coupling strength between the channel waveguide and the defect resonant ring is different , and the filter wavelength can be adjusted when the total size of the structure is not changed , and the filtering of the wider frequency band is realized , and the transmittance thereof is effectively adjusted .

【學(xué)位授予單位】：湖南大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN814

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 王玲玲;張振;王柳;孫斌;翟翔;李權(quán);李磊;;基于矩形諧振腔MIM波導(dǎo)結(jié)構(gòu)的表面等離子體帶阻濾波器[J];湖南大學(xué)學(xué)報(bào)(自然科學(xué)版);2012年05期

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本文編號(hào)：1719807