An example embodiment relates to a photonic integrated circuit device and a method for its manufacture. An example device includes a planar detector having at least one photodetector. The device may further include a waveguide layer arranged substantially parallel to the planar detector, the waveguide layer including a first integrated waveguide for guiding a first light signal. A cavity may be formed in the waveguide layer in a region spaced away from the edges of the waveguide layer such as to terminate the first integrated waveguide in that region. A first reflective surface may be provided in the cavity to reflect the first light signal guided by the first integrated waveguide toward a first photodetector of the planar detector.