Abstract: An integrated optical 2.times.2 changeover switch having four waveguide directional couplers has two wageguide directional couplers cascaded in each path from a port on one side to a port on the other side. Only two electrodes control the switch states of all four couplers. Crosstalk is guided to unused ports of the directional couplers. The extinction ratio is the sum of the extinction ratios of the cascaded couplers in its path. Additional waveguide couplers can be placed in the path of the crosstalk to improve the extinction ratio further.