Improved tolerance to the combined effect of in-band crosstalk and chromatic dispersion in partial DPSK systems

We use simulations to investigate the influence of the value of the differential delay of the Mach-Zehnder interferometer (MZI) demodulator in differential phase-shift-keyed (DPSK) systems when the system is limited by the combined effect of chromatic dispersion and in-band crosstalk. It is found that the dispersion and filtering tolerance improvement which is realized when the delay is less than one bit-period is preserved in systems with strong in-band crosstalk.