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.