Wavelength locking a fast-switching tunable laser

We demonstrate wavelength locking in a widely tunable fast-switching laser module that accesses 64 ITU channels with 50-GHz spacing and switches wavelength in under 50 ns. We use a Fabry-Pe/spl acute/rot etalon to stabilize the laser frequency against long-term drifts. We demonstrate locking while continuously switching with random channel schedules of 1-μs packets. The locked frequency accuracy of /spl plusmn/3 GHz is a factor of two improvement over operation without locking. We also present the dynamics of the frequency drift due to temperature variation in the laser, and show the correlation between the frequency offsets while locking and the electrical power dissipated in the tuning sections.