The invention relates to a wavelength division multiplexing optical receiver that is provided with a polarization splitting grating coupler and a driving method for the same, where the power consumption is reduced, and at the same time, a degradation in the receiver sensitivity is suppressed. Two monitor photodetectors configured to monitor the light intensity of a first polarization component and a second polarization component separated by a polarization splitting optical coupler are provided, and a control circuit is provided in order to allow a semiconductor optical amplifier that amplifies the first polarization component and another semiconductor optical amplifier that amplifies the second polarization component in accordance with the signal intensity ratio of the two monitor photodetectors to amplify light with different light gains.