Abstract: A passive optical network component comprising a model-locked laser, a dispersive nonlinear fiber coupled to the model-locked laser, and a modulator coupled to the dispersive nonlinear fiber, wherein the model-locked laser provides wavelengths for downstream modulations and enables upstream transmissions from a colorless optical network unit (ONU). Also disclosed is a colorless ONU comprising an optical circulator coupled to an incoming optical path and an outgoing optical path, and an optical injection-locking component coupled to the optical circulator, wherein the colorless ONU uses downstream optical signals from a model-locked laser as seed light to enable colorless upstream transmissions.