Dark–antidark solitons in waveguide arrays with alternating positive–negative couplings

We obtain dark and antidark soliton solutions in binary waveguide arrays with focusing and/or defocusing Kerr nonlinearity and with alternating positive and negative linear couplings between adjacent waveguides. For both stationary and moving solitons, we analyze the properties of these solutions in the presence of uniform and nonuniform nonlinearity along the array.