A Branch-Type TE/TM Wave Splitter Using a Light-Guiding Metal Line

Author

Yamazaki, Tomohide ; Yamauchi, Junji ; Nakano, Hisamatsu

Author_Institution

Fac. of Eng., Hosei Univ., Tokyo

Volume

25

Issue

3

fYear

2007

fDate

3/1/2007 12:00:00 AM

Firstpage

922

Lastpage

928

Abstract

The three-dimensional (3-D) beam-propagation method is applied to the analysis of a novel transverse electric/transverse magnetic (TE/TM) wave splitter using a light-guiding metal (Ag) line with an embedded dielectric (SiO₂) waveguide. Before analyzing the splitter, a mode converter with a tapered metal is designed to smoothly convert the guided mode of an embedded waveguide into the surface plasmon-polariton (SPP) mode, and vice versa. After demonstrating the effectiveness of a converter consisting of a two-step linear taper, the performance of the splitter is evaluated. To obtain a high coupling efficiency, the wavefront mismatch of the SPP mode is compensated for. In addition, a TE-pass polarizer is added to the TE output waveguide, reducing the undesirable TM wave. In contrast to the long device length of a conventional branch-type splitter (>1000 mum), the present splitter is found to have a noticeably short device length of less than 200 mum, although a loss of about 3 dB is observed for the TM wave. The crosstalk and the extinction ratio are, respectively, evaluated to be less than -15 dB and more than 15 dB for a branching angle of 16plusmn2deg at wavelengths of 1.31 and 1.55 mum

Keywords

optical beam splitters; optical crosstalk; optical design techniques; polaritons; silver; surface plasmons; 1.31 mum; 1.55 mum; Ag; TE/TM wave splitter; coupling efficiency; crosstalk; extinction ratio; light-guiding metal line; surface plasmon polariton; three-dimensional beam-propagation method; wavefront mismatch; Bandwidth; Extinction ratio; Magnetic analysis; Magnetic separation; Optical polarization; Optical surface waves; Optical waveguides; Plasmons; Surface waves; Tellurium; Beam-propagation method (BPM); TE/TM wave splitter; light-guiding metal line; mode converter; surface plasmon polaritons (SPP);

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/JLT.2006.889656

Filename

4147766