Abstract: An active photonic device includes a semiconductor substrate, an optically active region formed on the semiconductor substrate, the optically active region including a first electrical contact for initiating emission of photons and/or modulation of photons within the optically active region, an optical confinement structure defining a principal optical path through the active photonic device and through the optically active region, and a photodetector structure formed on the semiconductor substrate. The photodetector includes a second electrical contact displaced from, and substantially electrically insulated from, the first electrical contact and overlying at least part of the principal optical path, the photodetector for receiving carriers generated by emitted photons.