US Patent 7598527 Monitoring photodetector for integrated photonic devices

A laser and detector integrated on corresponding epitaxial layers of a single chip cooperate with on-chip and/or external optics to couple light of a first wavelength emitted by the laser to a single external device such as an optical fiber and to simultaneously couple light of a different wavelength received from the external device to the detector to provide bidirectional photonic operation. Multiple lasers and detectors may be integrated on the chip to provide multiple bidirectional channels. A monitoring photodetector is fabricated in the detector epitaxy adjacent one end of the laser.