Fiber-grating sensor for wavelength tracking in single-fiber WDM access PONs

A fiber-grating at the remote node of a single-fiber WDM passive optical network was used as a temperature sensor to track thermally-induced changes in a WDM router and derive an error signal that could be used for control of the transmitter source wavelengths to optimize network performance. The tracking method could also compensate for wavelength drift at the transmitter. We demonstrated a one-way optical power budget allowing greater than 20-km distance between the central office and remote node.