本文選題：光波導 + 聚合物��； 參考：《電子科技大學》2017年碩士論文

【摘要】：人們不斷開拓新技術來提升單模光纖(Single Mode Fiber,SMF)傳輸容量,包括密集波分復用、偏振復用以及高階調制等。然而,隨著計算機技術的快速興起,人們對信息需求量呈現(xiàn)出爆炸式增長。與此同時,單模光纖的傳輸極限估計在100 Tbps左右。不久的將來,單模光纖滿足不了這種信息量增長的需求,因此不得不尋求新技術來進一步提升光傳輸網(wǎng)絡的傳輸容量。模分復用(Mode Division Multiplexing, MDM)技術便是解決該問題的方案之一。模式復用/解復用器和模式轉換器是MDM系統(tǒng)的關鍵器件。就當前研究而言,模式的轉換與復用可以基于光子燈籠、Y分支、長周期光柵以及定向耦合器等波導結構實現(xiàn)。相比較于平面定向耦合器受限于兩波導等高的約束,垂直定向耦合器的設計更加靈活。論文基于垂直定向耦合器設計了 LP01-LP21a、LP01-LP21b以及LPo1-LP02模式轉換器。由于聚合物材料具有易加工的優(yōu)點,因此選擇EpoCore和EpoClad分別作為芯層和包層制作器件。論文核心內容如下。首先,論文研究了 LP01-LP21a模式轉換。運用耦合模理論設計了 LP01-LP21a模式轉換器,并運用微加工工藝制作了器件。制作所得的典型LP01-LP21a模式轉換器偏振弱相關。TE(TM)偏振在1530 nm波長處達到最佳轉換效率達98.2%(94.9%),在C波段隨著波長向長波場移動轉換效率逐漸下降,在1560 nm波長處降至90.1%(88.8%)。該器件的理論設計參數(shù)與實際制作所得器件參數(shù)基本上是一致的。其次,論文研究了 LP01-LP02以及LP01-LP21b模式轉換。區(qū)別于LP01-LP21a模式轉換器的設計,由于LP21b和LP02的簡并性,不能通過模式間直接耦合的方式實現(xiàn)LP01-LP02以及LP01-LP21b模式轉換。論文通過先把LP01耦合到E13,然后通過錐形波導過渡,把E13演變?yōu)長P21b或LP02。制作所得的LP01-LP02模式轉換器件由于多層結構的應力作用,導致器件偏振相關。TE偏振光實現(xiàn)LP01-LP21b模式轉換,TM偏振光實現(xiàn)LP01-LP02模式轉換。TE (TM)偏振在1530 nm波長處達到最佳轉換效率達98.0% (97.7%),隨著波長向長波長移動轉換效率急劇下降,在1560 nm波長處降至65.5% (55.5%)。制作所得的LP01-LP21b模式轉換器,由于制作所得器件兩波導截面尺寸與設計差別較大,模式的相位匹配程度不高,從而導致?lián)Q效率非常低。
[Abstract]:New technologies have been developed to enhance the transmission capacity of single Mode FiberMode SMFs, including dense wavelength Division Multiplexing, polarization Multiplexing and Higher-order Modulation. However, with the rapid rise of computer technology, the demand for information has increased explosively. At the same time, the transmission limit of single mode fiber is estimated to be about 100 Tbps. In the near future, single-mode optical fiber can not meet the need of increasing the amount of information, so it has to seek new technology to further enhance the transmission capacity of optical transmission networks. Mode Division Multiplexing (MDM) is one of the solutions to this problem. Mode multiplexer / demultiplexer and mode converter are key devices in MDM system. As far as current research is concerned, mode conversion and multiplexing can be realized based on photonic lantern Y branch, long period grating and directional coupler. The design of vertical directional coupler is more flexible than that of plane directional coupler limited by two waveguides. Based on the vertical directional coupler, LP01-LP21aer LP01-LP21b and LPo1-LP02 mode converter are designed. Because polymer materials are easy to process, EpoCore and EpoClad are chosen as core layer and cladding device respectively. The core contents of the thesis are as follows. Firstly, LP01-LP21a mode conversion is studied. The LP01-LP21a mode converter is designed by using the coupled mode theory, and the device is fabricated by micromachining technology. The polarization of the typical LP01-LP21a mode converter with weak polarization correlation has reached the optimum conversion efficiency at 1530 nm. The conversion efficiency of the typical LP01-LP21a mode converter decreases gradually with the wavelength moving to the long wave field at 1560 nm, and the conversion efficiency decreases to 90.1% at 1560 nm. The theoretical design parameters of the device are basically the same as those obtained in practice. Secondly, we study LP01-LP02 and LP01-LP21b mode conversion. Different from the design of LP01-LP21a mode converter, because of the degeneracy of LP21b and LP02, LP01-LP02 and LP01-LP21b mode conversion can not be realized by direct coupling between modes. First, LP01 is coupled to E13, and then through conical waveguide transition, E13 is transformed into LP21b or LP02. The fabricated LP01-LP02 mode conversion device is due to the stress of the multilayer structure. As a result, the polarization-dependent. Te polarizing light can realize LP01-LP21b mode conversion and TM polarization light realize LP01-LP02 mode conversion. The optimum conversion efficiency at 1530 nm is 98.0%, and the conversion efficiency decreases sharply with the shift of wavelength to long wavelength. At the wavelength of 1560 nm, it was reduced to 65.5% and 55.5%. The fabricated LP01-LP21b mode converter is very inefficient because the cross-section size of the two waveguides is different from the design and the phase matching degree of the mode is not high.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TN929.1

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本文編號：2011801