2015光通信原理与技术--04-20150325Joseph C Palais.pdfVIP

Op#cal ?Communica#ons: ? Principles ?and ?Technologies ? 2014/03/25 作业交 小作业：计算并画出当θ1=1o, ?3o,5o,10o,15o时的ray ?path ?in ?the ? fiber ?core ?with ?square ?law ?refrac#ve ?index ?的变化曲线， n1=1.46，a分别16和32，Δ分别对应取0.015和0.001。 第1章 光纤通信系统 第2章 光学概要 第3章 波动学基础 第4章 集成光波导 第5章 光纤波导 第6章 光源和光放大器 第7章 光检测器 第8章 耦合器与连接器 第9章 分布式网络和光纤器件 第10章 调制 第11章 噪声和检测 第12章 系统设计 Joseph C. Palais What have we learned so far Transmission ?characteris#cs ?of ? op#cal ?fibers ???Material ?absorp#on ?losses ? ü??Intrinsic ?absorp#on ? ü??Extrinsic ?absorp#on ? ???Linear ?scaNering ?losses ? ü??Rayleigh ?scaNering ? ü??Mie ?scaNering ? ???Nonlinear ?scaNering ?losses ? ü??S#mulated ?Brillouin ?scaNering ? ü??S#mulated ?Raman ?scaNering ? ???Fiber ?bend ?loss Numerical Aperture (NA) Normalized Frequency The normalized frequency is a dimensionless parameter and hence is also sometimes simply called the V number or value of the fiber. It combines in a very useful manner the information about three important design variables for the fiber: namely, the core radius a, the relative refractive index difference Δ and the operating wavelength λ. Mul#mode ? graded ?index ? fiber Mul#mode ?step ? index ?fiber Single ?mode ? step ?index ?fiber Snells law: the refractive index changes, the ray path bends in such a way that the product n(x)cosθ(x) remains constant ？ Ray ?paths ?in ?a ?homogeneous ?medium d 2x dz2 = 1 2 ?β 2 dn2 dx ? ? Ray ?paths ?in ?a ?homogeneous ?medium In ?a ?homogeneous ?medium, ?n2 ?is ?a ?constant d 2x dz2 = 1 2 ?β 2 dn2 dx ? d 2x dz2 = 0 the ?solu8on ?of ?which ?is x(z) = A+ Bz a ?straight ?line The ?ray ?paths ?in ?a ?homogeneous ? medium ?are ?straight ?lines. Ray ?paths ?in ?square ?law ?media ? d 2x dz2 = 1 2 ?β 2 dn2 dx ? ? n2 (x) = n1 2 1? 2Δ x a # $ % (