Title :
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
fDate :
6/1/2006 12:00:00 AM
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;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2006.874574