Electromagnetic Eigen-field Characteristics of Acousto-optic Waveguides with Transverse SAW
Among several optical devices,fundamental characteristics and processing systems of collinear optical switching device have been studied about optical dielectric waveguides on LiNbO3 crystal substrates.Conventional waveguide-type A-O devices use collinear interaction with mode coupling based on Bragg condition between optical waves and SAW both propagating in same directions.Collinear A-O devices of waveguide-type show sufficient performance for wavelength selective switching with narrow bandwidths.However,in these collinear A-O devices,since SAW propagation speed is very slow,interaction time is several micro seconds for 10mm waveguide device length.In A-O devices of optical waveguides using transverse A-O interaction,where SAW propagates transversely and at right angles to optical wave propagation direction,SAW propagation lengths needed for complete A-O interaction may become 10 1m and interaction time may be several nano seconds,with ultra high speed switching.In this paper,fundamental characteristics of transverse A-O interaction are studied as electromagnetic boundary value problem.Refractive indexes in optical waveguides induced by A-O effects with SAW are shown by sine functions.Wave field characteristics in inhomogeneous media of periodic structures for transverse directions given by A-O effects are analyzed by analytic method of Hills equations for transverse spectral functions.Electromagnetic fields in core and clad regions with periodic structures are shown by Mathieu functions.By boundary conditions,eigen equations of transverse type A-O waveguides are derived.Dispersion characteristics of A-O eigen modes are studied for wavelengths of optical waves and SAW,with acousto-optic coefficients for stable pass and unstable forbidden bands.Based on these fundamental field characteristics of A-O waveguides,mode couplings and switchings in transverse A-O waveguide devices consisting of coupled several optical waveguides controlled by SAW may be shown.
Yasumitsu Miyazaki
Faculty of Engineering,Aichi University of Technology 50-2 Manori,Nishihasama-cho,Gamagori 443-0047,Japan
国际会议
Progress in Electromagnetics Research Symposium 2013(2013年电磁学研究新进展学术研讨会)
台北
英文
129-134
2013-03-01（万方平台首次上网日期，不代表论文的发表时间）