Self-chaotization in coupled optical waveguides

We consider theoretically two coupled optical waveguides' with a varying barrier height along the waveguides direction. The barrier could be constructed by the elongated island with a reduced refractive index (that acts as a potential barrier), such that in the middle region it splits a waveguide into two weakly coupled parts. It is predicted by numerical simulations and analytical consideration that the presence of some imperfection of the system parameters can cause splitting of the injected laser beam and one will observe two intensity maximums at the output, while for small imperfections the input and output beam intensity distributions will be the same. The switching between two regimes could be achieved by changing the spectral width of the beam or the refractive index of the island. This nontrivial effect is explained by the possibility of transitions between the different eigenstates of the system in the region of large potential barrier heights. The mentioned effect could be used for all-optical readdressing and filtering purposes.