手性的階躍剖面及布拉格光纖模式分析
發(fā)布時(shí)間:2018-01-28 05:30
本文關(guān)鍵詞: 光纖光學(xué) 手性介質(zhì) 布拉格光纖 一維光子晶體 橫電磁模 空分復(fù)用 出處:《哈爾濱工業(yè)大學(xué)》2014年博士論文 論文類(lèi)型:學(xué)位論文
【摘要】:光纖通信技術(shù)在過(guò)去的幾十年中一直保持著高速發(fā)展,支撐著信息化程度越來(lái)越高的社會(huì)和經(jīng)濟(jì)。為了保持目前的發(fā)展勢(shì)頭,在光纖通信的物理層面上,我們需要不斷地開(kāi)發(fā)新型的光信號(hào)傳送媒質(zhì)和光信息處理器件。光纖是光纖通信系統(tǒng)的基礎(chǔ)組件,對(duì)其進(jìn)行的革新將具有根本性的意義。新型光纖的開(kāi)發(fā)可以從兩個(gè)角度開(kāi)展:改變光纖的幾何結(jié)構(gòu);使用新型介質(zhì)作為光纖的填充材料。對(duì)于前者,已經(jīng)發(fā)展得較為成熟的光子晶體光纖技術(shù)是其代表;對(duì)于后者,如考慮用手性介質(zhì)或負(fù)折射介質(zhì)作為光纖的填充材料,研究依然處于基礎(chǔ)階段。本論文以填充手性介質(zhì)的有限層光纖為研究對(duì)象,利用模式分析主要研究其中最特殊的兩類(lèi):手性階躍剖面光纖—最簡(jiǎn)單的手性光纖;手性布拉格光纖—最簡(jiǎn)單的手性光子晶體光纖。 本論文首先研究了手性有限層光纖的一般模式特性。考慮較為一般的介質(zhì)電磁參數(shù)(手性參數(shù)任意;介電常數(shù)和磁導(dǎo)率的實(shí)部同號(hào),實(shí)部的絕對(duì)值大于虛部的絕對(duì)值),發(fā)展了手性有限層光纖的模式理論,然后基于模式理論的鏡像對(duì)稱(chēng)性闡述了手性有限層光纖中模式分裂的物理內(nèi)涵:無(wú)論在非手性有限層光纖的哪一層中引入手性(結(jié)構(gòu)的鏡像對(duì)稱(chēng)性破缺),均會(huì)引起那些原本二度簡(jiǎn)并且互為鏡像的模式發(fā)生分裂(結(jié)構(gòu)所支持的態(tài)的鏡像對(duì)稱(chēng)性破缺)。 針對(duì)手性非負(fù)折射的階躍剖面光纖,導(dǎo)出了導(dǎo)模的截止條件,研究了光纖中的模式分裂問(wèn)題,發(fā)現(xiàn)了阻抗匹配條件下模式分裂的嚴(yán)格路徑,研究了阻抗失配條件下芯層和包層中的手性對(duì)模式分裂不同的貢獻(xiàn)方式。另外,指出了包層具有手性的阻抗失配階躍剖面光纖的單偏振模導(dǎo)行特性。 針對(duì)手性負(fù)折射的階躍剖面光纖,研究了橫電磁模導(dǎo)行的問(wèn)題,導(dǎo)出了橫電磁模的導(dǎo)行條件,指出了光纖中橫電磁模所具有的反直覺(jué)的性質(zhì)—模場(chǎng)任意性—模式的電磁場(chǎng)分布由任意的解析復(fù)變函數(shù)描述。基于橫電模獨(dú)特的模場(chǎng)空間分布性質(zhì),從概念上提出了一種新型的空分復(fù)用。 一維光子晶體光纖的光場(chǎng)約束特性可以從一維光子晶體的能帶理論獲得很好的理解。作為研究手性布拉格光纖的前提,本文整理了非手性一維光子晶體的能帶理論,發(fā)展了手性一維光子晶體的能帶理論。給出了非手性介質(zhì)界面上必然存在布儒斯特角的嚴(yán)格證明,從而解釋了為什么在非手性一維光子晶體中實(shí)現(xiàn)三維完全帶隙,原胞包含的介質(zhì)層數(shù)目至少為3。對(duì)于手性一維光子晶體,發(fā)現(xiàn)若巧妙地設(shè)計(jì)晶格結(jié)構(gòu),在原胞包含的介質(zhì)層數(shù)目為2的情況下即可以實(shí)現(xiàn)三維完全帶隙。 研究了僅芯層具有手性的布拉格光纖和具有完全帶隙手性包層的空芯布拉格光纖的模式特性。對(duì)于前者,指出了光纖支持圓偏振模的條件,并發(fā)現(xiàn)若在TM運(yùn)轉(zhuǎn)的非手性布拉格光纖的芯層中引入微弱手性,則可以使得該光纖同時(shí)具備波長(zhǎng)選擇和圓偏振選擇。對(duì)于后者,發(fā)現(xiàn)完全帶隙有望極大地壓制包層介質(zhì)的材料吸收對(duì)模式損耗的貢獻(xiàn)。
[Abstract]:Optical fiber communication technology has maintained a rapid development in the past few decades, supporting the increasingly high degree of information technology and social economy. In order to maintain the current momentum of development, at the physical level of optical fiber communication, we need to constantly develop new optical signal transmission medium and optical information processor. Optical fiber is the basic components optical fiber communication system, the innovation will have fundamental significance. The development of novel optical fiber can be carried out from two aspects: changing the geometrical structure of the fiber; the use of new media as a filling material fiber. For the former, it has developed more mature technology of photonic crystal fiber is its representative; for the latter, such as consider the use of chiral medium or negative refractive medium fiber as filling material, study is still in the basic stage. In this paper, filled with chiral media layer of Fiber Co. Object analysis is mainly based on pattern analysis. The most special two kinds are: chiral step profile fiber, the simplest chiral fiber, chiral Prague fiber, the most simple chiral photonic crystal fiber.
This paper firstly studies the general mode characteristics of chiral finite layer fiber. Considering the electromagnetic parameters of medium more general (chirality parameter arbitrary; the real part of the permittivity and permeability of the same number, the real part of the absolute value of the absolute value is greater than the imaginary part), the development of chiral model theory of finite layer of optical fiber, and then based on mirror symmetry model theory describes the physical connotation of chiral finite layer fiber mode splitting: both in the achiral finite layer fiber which layer of the introduction of chiral (mirror symmetry structure), will cause those who had two degeneracy and are mirror mode split (mirror symmetry breaking support structure of state).
For non chiral negative refractive index step profile fiber, cut-off condition of guided modes are derived, studied in fiber mode split, found a strict path split mode impedance matching conditions, study the chiral core and cladding impedance mismatch in the condition of different mode split way to contribute. In addition it is pointed out that the single polarization mode, clad chiral impedance mismatch step profile fiber guiding characteristics.
The chiral negative refractive index step profile fiber, on the transverse electromagnetic mode for the problem, derived the guidance conditions of transverse electromagnetic mode, points out the transverse electromagnetic mode fiber has the characteristics of counter intuitive mode field - mode field of arbitrary distribution by any analytical complex function description. The nature of the distribution of field space transverse electric mode unique mode based on the concept, proposed a new type of spatial multiplexing.
One dimensional photonic crystal fiber optical confinement properties can be from the band theory to obtain a good understanding of one-dimensional photonic crystal. As the premise of the research on chiral fiber Prague, this paper analyzed the energy band theory of achiral one-dimensional photonic crystal, the development of the band theory of chiral one-dimensional photonic crystal. The non chiral medium interface is inevitable there are strict proof of the Brewster angle, which explains why 3D complete band gap in achiral one-dimensional photonic crystals, dielectric layer number cell contains at least 3. of the chiral photonic crystal is found if the cleverly designed lattice structure, the dielectric layer number of cell contains 2 cases that can be the realization of three-dimensional complete band gap.
The only core layer chiral fiber Prague and has complete bandgap chiral cladding hollow core Prague fiber mode characteristics. For the former, pointed out that the fiber support circular polarized mode conditions, and found that if the introduction of chirality in the achiral weak core Prague fiber TM operation, can make the fiber at the same time with the wavelength selection and circular polarization. For the latter, found that complete band gap is expected to greatly suppressed the cladding material on the absorption loss contribution.
【學(xué)位授予單位】:哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】:博士
【學(xué)位授予年份】:2014
【分類(lèi)號(hào)】:TN929.11
【參考文獻(xiàn)】
相關(guān)期刊論文 前1條
1 董建峰;李杰;;Guided modes in the chiral negative refractive index fiber[J];Chinese Optics Letters;2010年11期
,本文編號(hào):1469901
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