Certain embodiments of the present invention provide a monitoring system
configured to monitor output wavelengths, power, and channel switching of
tunable lasers employed in an optical transmitter and provide feedback to
those lasers, e.g., to lock on the wavelengths corresponding to optical
channels in the transmitter. The monitoring system has a monitoring
switch fabric, such as an optical waveguide grating (AWG), and one or
more photodetector arrays coupled to the transmitter. Optical channels in
the monitoring AWG may be offset relative to the optical channels in the
transmitter and shaped to allow more sensitive monitoring of, e.g.,
wavelength drifting of the tunable lasers. The monitoring system may
track the lasers in a non-disruptive continuous manner while data is
transmitted through the transmitter.