發(fā)布時間：2018-03-13 19:27

  本文選題：偏振分束器　切入點：硅基光波導　出處：《中南民族大學》2015年碩士論文　論文類型：學位論文

【摘要】：偏振是光波的基本屬性之一。研究不同偏振態(tài)的光波在傳輸過程中的性質(zhì),以及研究把不同偏振態(tài)的光波高效分離的方法,在光通信、偏振檢測與分析、激光調(diào)制、偏振成像和投影系統(tǒng)等領(lǐng)域有著巨大的理論與應用價值。本文使用平面波法和有限時域差分法,針對通常研究只討論硅納米狹縫波導中準橫磁模(TM)偏振傳輸?shù)膯栴},較全面的研究了準TM偏振和準橫電模(TE)偏振在硅納米狹縫波導中雙偏振傳輸?shù)膸捯约肮鈭龇植继匦?針對常規(guī)硅偏振分束器尺寸較大的問題,設(shè)計了一種基于非對稱定向耦合波導的新型緊湊型偏振分束器。本文的主要工作有:(1)采用三維數(shù)值研究法,研究了硅基縫波導的偏振特性。通過調(diào)節(jié)狹縫波導中硅介質(zhì)的寬度,獲得了帶寬達320.6 nm的雙偏振單模狹縫波導;并且發(fā)現(xiàn)在該帶寬范圍內(nèi),準TE偏振的電場強度在狹縫中能夠獲得增強,而對準TM偏振則不具有增強作用。這為進一步設(shè)計硅基縫波導的偏振相關(guān)器件奠定了基礎(chǔ)。(2)采用平面波法設(shè)計了一種二維非對稱定向耦合波導的緊湊型偏振分束器,并使用有限時域差分法驗證了偏振分束器設(shè)計的正確性。該分束器的耦合區(qū)設(shè)計長度最小為2.88μm,驗證長度為2.75μm;兩種方法的結(jié)果符合得很好,表明偏振分束器的設(shè)計是正確的。(3)基于上述設(shè)計的非對稱偏振分束器,又研究了偏振分束器輸入和輸出端S型耦合彎曲波導的長度和彎曲角度,非對稱定向耦合結(jié)構(gòu)中條形波導和周期型波導之間的狹縫寬度對偏振分束器消光比和插入損耗的影響。二維有限時域差分法表明,當中心波長為1550 nm時,彎曲角度為16 o和狹縫寬度為99.05nm的帶S型彎曲耦合輸入輸出段的偏振分束器,在100 nm的帶寬內(nèi),TE和TM模式的消光比均大于15 dB,且插入損耗均小于0.8 dB。這為設(shè)計和制作超小型硅基偏振分束器奠定了基礎(chǔ)。
[Abstract]:Polarization is one of the basic properties of light waves. The properties of different polarization states in the process of transmission are studied, and the methods to efficiently separate the different polarization states of light waves in optical communication, polarization detection and analysis, laser modulation are studied. Polarization imaging and projection systems have great theoretical and practical value. In this paper, the plane wave method and the finite difference time-domain method are used to study the polarization propagation of quasi-transverse magnetic mode (TMM) in silicon nanoscale slit waveguides. The bandwidth and optical field distribution of quasi-TM polarization and quasi-transverse electric mode polarization polarization in silicon nanoscale slit waveguide are studied in detail, aiming at the problem of the larger size of conventional silicon polarization splitter. A new compact polarization beam splitter based on asymmetric directional coupling waveguide is designed. The main work of this paper is to study the polarization characteristics of silicon based slit waveguide by using three-dimensional numerical method. By adjusting the width of silicon dielectric in slit waveguide, A dual-polarization single-mode slit waveguide with a bandwidth of 320.6 nm is obtained, and it is found that the electric field intensity of quasi-te polarization can be enhanced in the slit within this bandwidth range. The polarization alignment of TM has no enhancement effect, which lays a foundation for the further design of polarization-related devices for silicon-based slit waveguides. A compact polarization splitter for two-dimensional asymmetric directional coupled waveguides is designed by plane wave method. The design of the polarization beam splitter is verified by the finite difference time domain method. The minimum design length of the coupling region is 2.88 渭 m and the verification length is 2.75 渭 m. The results of the two methods are in good agreement with each other. It is shown that the design of polarization splitter is correct. (3) based on the asymmetric polarization splitter designed above, the length and bending angle of the S-type coupling curved waveguide at the input and output ends of the polarization splitter are studied. The effect of slit width between strip waveguide and periodic waveguide on extinction ratio and insertion loss of polarization splitter in asymmetric directional coupling structure. The two-dimensional finite-difference time-domain method shows that when the central wavelength is 1550 nm, A polarization beam splitter with S-type bending coupling input and output section with a bending angle of 16 o and a slit width of 99.05 nm, The extinction ratio of te and TM modes is greater than 15 dB and the insertion loss is less than 0.8 dB in 100 nm bandwidth, which lays a foundation for the design and fabrication of a miniature silicon based polarization beam splitter.
【學位授予單位】：中南民族大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN252
，

本文編號：1607830