InGaAsP/InP MQW directional coupler switch with small and low-loss bends for fiber-array coupling

We report on a compact InGaAsP/InP MQW directional coupler switch with spacing between the waveguides at the input and the output facets larger than 125 μm, required for the fiber-array coupling, by employing small low-loss bends. The total device length, including both the coupling and the bending regions, with the different optical confinements in the lateral direction is 2 mm. The coupling region of the switch is 420 μm, and the voltage-length product at switching is around 6 Vmm.