Abstract: Systems and techniques for mitigating spectral excursions in a passive optical network (PON) are described herein. A spectral excursion may be determined in the PON. The spectral excursion may indicate a laser transmission output on the PON at a wavelength that is outside a designated wavelength range. A duration may be identified for the spectral excursion. A first preamble offset may be generated using the duration of the spectral excursion. A round trip delay for the PON and a local time of day may be determined. The first preamble offset, the round trip delay, and the local time of day may be transmitted to an optical line terminal (OLT).