Design and analysis of low loss MMI based 4×4 optical switch using Benes architecture with SOAs

摘要

This paper presents an overview of self-imaging principle used in MMI couplers and also explains the application of multimode waveguide as an optical switch. The application of MMI coupler to realize a 2×2 optical switch has been explained by varying the refractive indices of various regions of MMI section by only 1-2% and the switch is found to exhibit 2-10% loss for various coupling states at different power inputs. Then the basic 2×2 switch is exploited in design of 4×4 benes switch. Benes switch is used as it is suitable for large switches requiring fewer SOAs which make it a good candidate for further use in higher order switches. Simulation results are shown. Power coupling losses occurring in 4×4switch are compensated using minimum number of SOAs with low input injection current of the order of 10-20mA.