Wavelength-tracking dispersion compensator

A method of operating a wavelength-tracking dispersion, WT-DC, compensator comprising the steps of:

• receiving an input signal at a chromatic dispersion compensator having a temperature-dependent wavelength characteristic and operating at a reference wavelength,
• receiving the input signal at a wavelength monitor, having a temperature-dependent wavelength characteristic and operating at the same reference wavelength as the dispersion compensator and generating an optical output signal,
• detecting the optical output signal and generating a control signal that indicates when the wavelength of the received input signal is misaligned with the reference wavelength of the dispersion compensator, and
• changing the temperature of both the dispersion compensator and the wavelength monitor in response to the control signal so as to change the reference wavelength of the dispersion compensator and the wavelength monitor to align with the wavelength of the received input signal.

A wavelength-tracking dispersion compensator, WT-DC, comprising

• a chromatic dispersion compensator, having a temperature-dependent wavelength characteristic, and operating at a reference wavelength for receiving an input signal that has a wavelength that can vary over time,
• a wavelength monitor, having a temperature-dependent wavelength characteristic, and operating at the same reference wavelength as the dispersion compensator for receiving the input signal and for generating an optical output signal,
• a detector control circuit for detecting the optical output signal from the wavelength monitor and for generating a control signal that indicates when the wavelength of the received input signal is misaligned with the reference wavelength of the dispersion compensator, and
• a temperature controller for changing the temperature of both the dispersion compensator and the wavelength monitor in response to the control signal so as to change the reference wavelength of the dispersion compensator and the wavelength monitor to align with the wavelength of the received input signal.