Large group-index bandwidth product empty core slow light photonic crystal waveguides for hybrid silicon photonics

Abstract

This paper investigates the slow light propagation in silicon on insulator wide slot photonic crystal waveguides (PCWs). Two design schemes are presented, relying on the dispersion engineering of hole lattice and slot, respectively. Mode patterns and band diagrams are calculated by 3D-plane wave expansion method. Then, coupling and slow light propagations are modeled using finite difference time domain method in a full Mach-Zehnder interferometer (MZI). Results show high amplitudes interference fringes and high coupling efficiencies. Fabrication and measurement of devices lead to slow light propagation with group indices above 50, while multiple scattering and localized modes near the band edge also observed. This study provides insights for losses in hollow core slot high group index waveguides.

Keywords

silicon photonics / photonic crystals (PC) / slot waveguides / slow waves

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Acknowledgements

The authors acknowledge financial support from the ANR POSIPLOT funding program. Charles Caër acknowledges a scholarship from the French Ministry of Higher Education and Research. The authors acknowledge Prof. Nicolas Dubreuil, Dr. Philippe Lalanne, Dr. Sylvain Combrié and Dr. Alfredo de Rossi for fruitful discussions.

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2014 Higher Education Press and Springer-Verlag Berlin Heidelberg