A Study of Hybrid Supermodes on the Application of Optical Polarization Converters

• Main Authors: Hung-Wei Chen, 陳泓維
• Other Authors: Rei-Shin Chen
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/36234343673245921705

碩士 === 龍華科技大學 === 電機系碩士班 === 92 === This work is a study of optical polarization converters based on the structure proposed by Mertens et al. in 1995. The structure is a ridge waveguide built on an InP substrate and a loaded strip on an InGaAsP layer. Hybrid supermodes can be obtained under suitable waveguide parameters and are utilized to achieve polarization conversion. Device characteristics and effects of waveguide parameters are both studied in this work. Moreover, passive polarization converters on lithium niobate substrates by the principle of hybrid supermodes are also studied. By varying the refractive index difference and the layer thickness, an optimal strip width can be obtained which minimizes the difference of propagation constants between the fundamental TM mode and the first order TE mode. The achieved polarization converters have advantages of high conversion efficiency, low loss, symmetric waveguides which are easy to fabricate, and free of periodic structures. A complete study about the waveguide structures and dimensions is given in the work.