Chromatic dispersion discriminator

A dispersion discriminator for determining the amount of dispersion in an amplitude modulated optical signal from two or more portions of the optical signal, the dispersion discriminator comprising:

• a first dispersion leg for causing a first additional amount of dispersion in a first portion of the optical signal;
• a second dispersion leg for causing a second additional amount of dispersion in a second portion of the optical signal, said first and second additional amounts being opposite in polarity;
• and
• a dispersion detector for receiving the first and second portions from the respective dispersion legs, determining the amount of dispersion in the optical signal by detecting a difference between the amount of dispersion in the received first and second portions, and providing an indication of said amount of dispersion in the optical signal.

A dispersion discriminator for determining the polarity and magnitude of dispersion in an amplitude modulated optical signal, the dispersion discriminator comprising:

• an input port for receiving the optical signal;
• an output port for transmitting an output signal indicating the polarity and magnitude of dispersion in the optical signal;
• a splitter having an input coupled to the input port and having at least two outputs, the splitter operable to divide the optical signal into at least first and second portions;
• a positive dispersion leg having two ends, one of which is coupled to one output of the splitter, the positive dispersion leg being operable to add an amount of positive dispersion to the first portion;
• a negative dispersion leg having two ends, one of which is coupled to the other output of the splitter, the negative dispersion leg being operable to add an amount of negative dispersion to the second portion;
• and
• a dispersion detector having an output coupled to the output port and having two inputs, each input coupled to a respective other end of the positive and negative dispersion legs, the dispersion detector being operable to determine the polarity and magnitude of dispersion in the optical signal by comparing the first and second portions received from the first and second dispersion legs and to transmit an indication of the polarity and magnitude of dispersion in the optical signal via the output signal.