University of Electronic Science and Technology of China 4 1.基本光波导单元结构Y分支 1956 图7-9.Y分支结构示意图 对称Y分支-模式分离或模式转换 MCF (Mode Conversion Factor) MCF= 2B4-B8 >0.43 0V(B4+B)2-(2km)2 -两波导分支间折射率；k-自由空间波夫 16
University of Electronic Science and Technology of China 16 对称Y分支-模式分离或模式转换 n--两波导分支间折射率；k--自由空间波矢 图7-9. Y分支结构示意图 𝜽 0.43 ( ) (2 ) 2 MCF 2 2 + − − = A B kn A B MCF （Mode Conversion Factor） A 𝐁 1. 基本光波导单元结构-Y分支
University of Electronic Science and Technology of China 1.基本光波导单元结构Y分支 1956 h B B A B First-Even First Even +Odd Supermodes First-Odd Supermode Supermode 3dB Attenuation 2 Fundamental 图7-10.Y分 Second(First-Odd) Mode Fundamental Mode Mode (a) (b). 支基本功能 B A B A B A B Second-Even Second-Odd Fundamental Supermode Supermode Fundamental Mode Mode 4 3 Third(Second-Even) Fourth(Second-Odd) Fundamental Second(First-Odd) Mode Mode Mode Mode (a) (b). (a. (b) Ref.1 J.D.Love and N.Riesen,"Single-,few,and multimode Y-junctions,"J.Lightw. Technol,vol.30,no.3,pp.304-309,Feb.2012. 17
University of Electronic Science and Technology of China 17 图7-10. Y分 支基本功能 Ref. 1 J. D. Love and N. Riesen, “Single-, few, and multimode Y-junctions,” J. Lightw. Technol., vol. 30, no. 3, pp. 304-309, Feb. 2012. 1. 基本光波导单元结构-Y分支 1 2 3 4
University of Electronic Science and Technology of China 4 1.基本光波导单元结构Y分支 1956 (a)折射率分布 (b)光场传输特征 Refractive Index Propagation Optical Field Propagation 1.510 1.00 1,505 500 .495 490 00 2000. 2000. 1500. 1500 1000 1000 10 00 500 500 17.184 0.210 -17.605 7 17.184 0.210 -17.605 35.000 -35.000 图7-11束传播软件模拟的对称Y分支光波导-1 18
University of Electronic Science and Technology of China 18 图7-11 束传播软件模拟的对称Y分支光波导-1 （a）折射率分布 （b）光场传输特征 1. 基本光波导单元结构-Y分支
University of Electronic Science and Technology of China 1.基本光波导单元结构Y分支 1956 Optical Field Propagation Optical Field Propagation 1.00 .00 0.75 00 0.50 0.25 50 0.00 6265 1251 18755 2002.0 626.5 12510 1875.5 2500.0 Power in Path 1000 2000 图7-12束传播软件模拟的对称Y分支光波导-2 19
University of Electronic Science and Technology of China 19 图7-12 束传播软件模拟的对称Y分支光波导-2 1. 基本光波导单元结构-Y分支
University of Electronic Science and Technology of China 1.基本光波导单元结构Y分支 1956 800.00 11111 1200.000 1160000 Refractive Index Propagation 20 × 61 0 -10 500 1000 1500 2000 .0 Optical Field Propagation Optical Field Propagation 20 10 0 0 2 500 1000 1500 200 500. 7 1000 1500 2000 图7-13束传播软件模拟的非对称Y分支光波导-1 20
University of Electronic Science and Technology of China 20 图7-13 束传播软件模拟的非对称Y分支光波导-1 1. 基本光波导单元结构-Y分支