Studies on characteristics of optical add/drop multiplexer using an asymmetric grating coupler

Research Project

Project/Area Number	14550389
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	情報通信工学
Research Institution	Osaka Electro-Communication University
Principal Investigator	MURAKAMI Yasuji Osaka Electro-Communication University, Faculty of engineering, Professor, 工学部, 教授 (30330153)
Project Period (FY)	2002 – 2003
Project Status	Completed (Fiscal Year 2003)
Budget Amount *help	¥3,600,000 (Direct Cost: ¥3,600,000) Fiscal Year 2003: ¥700,000 (Direct Cost: ¥700,000) Fiscal Year 2002: ¥2,900,000 (Direct Cost: ¥2,900,000)
Keywords	Add / Drop optical multiplexer / grating coupler / optical fiber coupler / 平面光導波路
Research Abstract	In the project, we proposed a new structure of optical add/drop multiplexer for use of optical routers in photonic networks and tried to study the optical characteristics of devices produced by way of experiment. Summary of research results, which we studied in this project, is as follows : (1)Optical add/drop multiplexer, which we studied, has a directional coupler structure with periodic refractive index changes. Optical power with a specific wavelength is added or dropped in this device. In this project, we proposed a new structure, and clarified the characteristics by both theoretical investigations and numerical calculations. (2)We tried to produce the new structure of optical add/drop multiplexer, which we theoretically studied, by way of experiment. Method for trial production is polishing of the side faces of optical grating fibers. We are now going on, and did not finish the studies. However, we found conditions for polishing, by which we can get uniform polishing side faces with reproduction. Detailed results are as follows : 1.100% coupling efficiency is obtained between even mode and odd mode in the asymmetric grating coupler. 2.More than 90% refection efficiency is obtained for specific parameters in symmetric grating coupler, which has not yet been reported. 3.The new optical coupler proposed is hopeful for realization of small size optical multiplexers. 4.It is difficult to control polishing faces precisely in optical fibers. More studies, are needed to produce the optical fiber grating coupler by way of experiment.