A Modified Semivectorial BPM Retaining the Effects of the Longitudinal Field Component and Its Application to the Design of a Spot-Size Converter

Author

Yamauchi, Junji ; Nito, Yuta ; Nakano, Hisamatsu

Author_Institution

Fac. of Eng., Hosei Univ., Koganei, Japan

Volume

27

Issue

13

fYear

2009

fDate

7/1/2009 12:00:00 AM

Firstpage

2470

Lastpage

2476

Abstract

For the analysis of a z -variant optical waveguide with high-index contrast by the beam-propagation method (BPM), the error often grows up during the propagation process. In this paper, the formulation of the BPM is revisited, taking into account the effects of the longitudinal field component. The improvement in accuracy is demonstrated through the analysis of a vertically tapered rib waveguide. The power expression based on the Poynting vector is also employed to improve the power conservation property. As an application, the present technique is applied to the design of a spot-size converter composed of a multicore structure. It is numerically demonstrated that the use of a curvilinearly tapered core leads to a conversion length of 570 mum, which is 42% less than the length of a linearly tapered core, with a coupling efficiency of 97% being maintained at a wavelength of 1.55 mum.

Keywords

optical design techniques; optical waveguide theory; refractive index; rib waveguides; vectors; Poynting vector; beam-propagation method; coupling efficiency; curvilinearly tapered core; efficiency 97 percent; high-index contrast; longitudinal field component; multicore structure; power conservation property; semivectorial BPM; size 570 mum; spot-size converter design; vertically tapered rib waveguide; wavelength 1.55 mum; z -variant optical waveguide; Beam-propagation method (BPM); power conservation; spot-size converter (SSC);

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/JLT.2008.2011496

Filename

4815434