WAVELENGTH TRACKING OF A REMOTE WDM ROUTER IN A PASSIVE OPTICAL NETWORK

We propose, analyze, and demonstrate a simple, robust method which ena bles a laser to track uncontrolled changes in a remotely located WDM d evice, As opposed to locking to a wavelength standard, our method lock s the wavelength comb of a tunable DBR to a waveguide grating router ( 200-GHz channel spacing), We have demonstrated tracking at a 1 C/min t emperature slew rate without requiring sacrificial channels, a pilot t one, or analog dithering circuitry, We discuss tradeoffs between step size, slew rate, measurement accuracy, and power penalty.