A study on the enhancement of refractive index in Ti:LiTaO$_{3}$ optical waveguides by Zn-vapor diffusion

Zn-Vapor확산에 의한 Ti:LiTaO$_{3}$ 광도파로의 굴절률 증가에 관한 연구

  • 정홍식 (홍익대학교 전자전산공학과) ;
  • 정영식 (시립인천대학교 전기공학과)
  • Published : 1996.03.01

Abstract

A double diffusion technique is developed to enhance the effective mode index of optical waveguides in $LiTaO_3$. It consists of Zn diffusion from the vapor phase at relatively low temperatures (750->$800^{\circ}C$), into waveguides initially produced by Ti indiffusion at higher temperature (1150->$1200^{\circ}C$). Both X- and Z-cut substrates are investigated. A model that combines profiles of both diffusion is formulated to calculate the expected effective index values for planar waveguides. Good agreement is found between experimental results and model predictions which assume that the initial Ti profile is not affected by the lower temperature Zn diffusion. Effective index enhancements as high as 0.005 and 0.003 are obtained by this method for the fundamental extraordinary and ordinary modes, respectively.

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