Radiation loss of grating-assisted directional couplers using the Floquet-Bloch theory

Author

Sun, Nai-Hsiang ; Chou, Chih-Cheng ; Chang, Hung-Wen ; Butler, Jerome K. ; Evans, Gary A.

Author_Institution

Dept. of Electr. Eng., I-Shou Univ., Kaohsiung, Taiwan

Volume

24

Issue

6

fYear

2006

fDate

6/1/2006 12:00:00 AM

Firstpage

2409

Lastpage

2415

Abstract

The Floquet-Bloch theory (FBT) is used to determine the radiation loss of a grating-assisted directional coupler. Improper waves obtained by FBT represent leakage and produce radiation loss along the transverse direction. By summing the fields of all leaky harmonics, the power flow radiated into the superstrate and substrate can be calculated from Poynting´s theorem. However, the locations at which these summations occur impact the accuracy. An analytic formula for radiation loss is also derived. Results from both the FBT and the analytic formula are compared with results obtained using the coupled-mode theory.

Keywords

coupled mode analysis; diffraction gratings; integrated optics; optical directional couplers; optical losses; Floquet-Bloch theory; Poynting theorem; coupled-mode theory; grating-assisted directional coupler; radiation loss; Councils; Directional couplers; Flyback transformers; Gratings; Load flow; Optical losses; Optical waveguides; Power system harmonics; Resonance; Sun; Floquet–Bloch theory (FBT); gratings; optical directional couplers;

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/JLT.2006.874574

Filename

1643800