Multimode waveguide based directional coupler

• SOI based directional couplers are designed with symmetrical and asymmetrical configurations.
• Three fundamental modes are coupled in a multi-mode semi-triangular ring-resonator configuration.
• Couplers are designed with effective index method and their structural parameters are optimized.
• Performance of the couplers are analyzed in terms of cross-talk, mode overlap factor, coupling length and coupling efficiency.

The Silicon-on-Insulator (SOI) based platform overcomes limitations of the previous copper and fiber based technologies. Due to its high index difference, SOI waveguide (WG) and directional couplers (DC) are widely used for high speed optical networks and hybrid Electro-Optical inter-connections; TE00–TE01, TE00–TE00 and TM00–TM00 SOI direction couplers are designed with symmetrical and asymmetrical configurations to couple with TE00, TE01 and TM00 in a multi-mode semi-triangular ring-resonator configuration which will be applicable for multi-analyte sensing. Couplers are designed with effective index method and their structural parameters are optimized with consideration to coupler length, wavelength and polarization dependence. Lastly, performance of the couplers are analyzed in terms of cross-talk, mode overlap factor, coupling length and coupling efficiency.