Analysis of light coupling in AlxGa1-xAs waveguide arrays

Light propagation in arrays of AlxGa1-xAs waveguides is studied. The power coupling constant between two adjacent waveguides is precisely measured as waveguide material and structure is varied. Aluminum concentration contrast between waveguide core/cladding layers and waveguide width/height produce an asymmetric effective refractive index between linearly polarized modes, which in turn causes a polarization dependence of the coupling constants. Experimental measurement results agree well with an analytical model. The sensitivity of coupling constant to the waveguide parameters is analyzed. Through a careful geometric design, comparable coupling constants can be achieved in three waveguide arrays with different structure. Similar formation processes of discrete spatial optical solitons are observed respectively, confirming that the parameterization in the discrete nonlinear Schrodinger equation characterizes waveguide arrays. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

Light propagation in arrays of AlxGa1-xAs waveguides was studied, with the power coupling constant between adjacent waveguides measured precisely. The polarization dependence of coupling constants was observed due to asymmetric effective refractive index between linearly polarized modes. Through careful geometric design, comparable coupling constants were achieved in three waveguide arrays with different structures.