Accurate theoretical analysis of light transition in three-waveguide directional coupler based on Invariant Engineering

摘要

We proposed two novel three-waveguide couplers with exact passage designed by Invariant Engineering. The light completely transfer from one waveguide to the other in these two couplers, but the propagation ways are different. An important feature of our devices is that the length can be shorten by modulated parameter v. In addition, we show that beam splitters can be constructed by the modulated length.