Optical waveguides and optical transceivers are formed on one main surface of a semiconductor substrate. A light source is provided on one side surface of the semiconductor substrate, and emits light to the optical waveguides. In each of the optical transceivers, when a voltage is applied to a silicon layer, an optical resonator resonates with any one of the light components traveling through the optical waveguides, and emits the light component to an optical transmission member. In addition, in each of the optical transceivers, when a voltage is applied to the silicon layer, another optical resonators resonate with light traveling through the optical transmission member and emit the resonance light to photodetectors, respectively.