Theory of variable-ratio power splitters using multimode interference couplers

Author

Lagali, N.S. ; Paiam, M.R. ; MacDonald, R.I.

Author_Institution

Dept. of Electr. Eng., Alberta Univ., Edmonton, Alta., Canada

Volume

11

Issue

6

fYear

1999

fDate

6/1/1999 12:00:00 AM

Firstpage

665

Lastpage

667

Abstract

In this letter, we analyze the integrated optical N/spl times/N generalized Mach-Zehnder interferometer (GMZI) employing multimode interference (MMI) couplers. A transfer matrix is used to derive analytic expressions for the intensity distribution at the output ports of the GMZI as a function of the phase shifts applied to the arms. These expressions form a system of nonlinear equations which are numerically solved for the phase shifts, enabling a new interpretation of the GMZI as a variable-ratio power splitter. The performance of the GMZI has been simulated, and it is found that the power splitting ratio is tolerant to both the accuracy of the applied phase shifts and to fluctuations in wavelength.

Keywords

Mach-Zehnder interferometers; fluctuations; integrated optics; optical beam splitters; optical couplers; optical waveguide theory; analytic expressions; applied phase shifts; integrated optical generalized Mach-Zehnder interferometer; intensity distribution; measurement accuracy; nonlinear equations; output ports; phase shifts; power splitting ratio; transfer matrix; variable-ratio power splitter; variable-ratio power splitters; wavelength fluctuations; Arm; Couplers; Integrated optics; Interference; Nonlinear optics; Optical devices; Optical interferometry; Optical waveguides; Phase shifting interferometry; Transmission line matrix methods;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/68.766778

Filename

766778