Preliminary experimental results are reported on two‐wavelength switching in a GaAs‐based multiple quantum well planar directional coupler. It is verified that a novel design of the multiple quantum well (MQW) coupling region leads to a wavelength multiplexing/demultiplexing/switching operation. It is shown that control of such a function can be exercised by either the wavelength of operation or by an applied electrical voltage through exciton resonance effects in the MQW layer. The layer structure exhibits two exciton‐resonance peaks at which wavelength‐selective switching can be achieved.