An apparatus is provided in which a photodiode supported on a planar light wave circuit assembly and arranged such that a photosensitive portion of the photodiode is aligned along an optical path from the output of the planar light wave circuit to the photodiode of the planar light wave circuit assembly. The photodiode is arranged such that a spot size of light output from the planar light wave circuit is incident on the photosensitive portion such that an optical signal transmitted by the light output is converted to an electric signal by the photodiode. A mounting structure is arranged between the planar light wave circuit assembly and the photodiode in order to support the photodiode on the planar light wave circuit assembly. The optical path of the light output from the planar light wave circuit does not contain any refractive optical elements.