Wavelength drift of burst-mode DML for TWDM-PON [invited]

Thermally tunable burst-mode directly modulated lasers (DMLs) are the lowest-cost choices for the optical network units in time and wavelength division multiplexed passive optical network (TWDM-PON) systems. However, a fast wavelength drift caused by the burst-mode operation of this directly modulated distributed feedback laser needs to be considered. The drift can result in power penalties by effectively reducing the received optical power and also in crosstalk penalties when the signal drifts into neighboring channels after passing through the wavelength division multiplexed filter. In this paper, we report measurements and mitigation methods for this unwanted wavelength drift.