In this paper, a new technique is developed to improve high index contrast multimode interference (MMI) coupler performance. The technique is based on removing modal phase errors by introducing a perturbation in the lateral refractive index of the MMI section. Simulation results for several MMI devices show that this technique is able to provide extremely low excess losses and imbalance for all situations.
© 2009 IEEE
Inigo Molina-Fernández, Alejandro Ortega-Moñux, and Juan Gonzalo Wangüemert-Pérez, "Improving Multimode Interference Couplers Performance Through Index Profile Engineering," J. Lightwave Technol. 27, 1307-1314 (2009)