The optical device includes a waveguide on a base. The waveguide is configured to guide a light signal through a light-transmitting medium to a light sensor. The light sensor includes a sensor waveguide on the base. The sensor waveguide receives the light signal from the input waveguide. Additionally, the sensor waveguide includes a light-absorbing medium having an input side. The input side is interfaced with the light-transmitting medium such that at least a portion of the light signal received by the sensor waveguide travels through the input side of the light-absorbing medium upon being received by the sensor waveguide. The light-absorbing medium includes doped regions. One or more of the doped regions each extends from within the light-absorbing medium to the input side of the light-absorbing medium.