Hello all, I have problems with the next issue: I need to design a 2*2 3-db multimode interference coupler. I found some articles about that, but they are all very hard. the two inputs are single mode. i need to know how to choose the refractive index and length and width of the coupler. also need to explore the field distribution along the device. If someone have an idea where to look for good explantions, or might have some and can help with instructions where to begin with.... That would be very nice of you, Thanks, Hanan L.