Title :
Optimized offset to eliminate first-order mode excitation at the junction of straight and curved multimode waveguides
Author :
Hirono, T. ; Kohtoku, M. ; Yoshikuni, Y. ; Lui, W.W. ; Yokoyama, K.
Author_Institution :
NTT Opto-Electron. Labs., Kanagawa, Japan
fDate :
7/1/1998 12:00:00 AM
Abstract :
Applications to equip semiconductor phased-array wavelength demultiplexers with nonbirefringent waveguides are increasing. In several applications, the waveguides are multimodal and elimination of first-order mode excitation is required for their design. The optimized offset for eliminating the first-order mode excitation at the junction of straight and curved waveguides with a two-dimensional (2-D) structure is analyzed theoretically. We assume that the waveguide has a laterally symmetric index profile. By the perturbation method, the offset is obtained to the first order in the inverse of the bending radius. The offset is simply expressed by the effective refractive indices of the straight waveguide.
Keywords :
arrays; bending; demultiplexing equipment; optical design techniques; optical waveguide theory; optimisation; perturbation theory; refractive index; symmetry; wavelength division multiplexing; 2D structure; bending radius; curved multimode waveguides; effective refractive indices; first-order mode excitation; laterally symmetric index profile; nonbirefringent waveguides; optical waveguide boundaries; optical waveguide theory; optimized offset; perturbation method; semiconductor phased-array wavelength demultiplexers; straight multimode waveguides; Optical crosstalk; Optical refraction; Optical waveguide theory; Optical waveguides; Perturbation methods; Planar waveguides; Semiconductor waveguides; Waveguide junctions; Waveguide theory; Waveguide transitions;
Journal_Title :
Photonics Technology Letters, IEEE
