Accurate computation of the BER in DPSK/MZI receiver with balanced detection thereafter of 40Gbit/s optical system

This paper analyses and achieves the accurate computational expression of nonlinear phase noise cos(Δϕ) in DPSK receivers using optical Mach-Zehnder interferometer (MZI) demodulation and balanced detection of 40Gbit/s system. It had been used in the BER computation expression considering all the noises to achieve a final accurate computation expression of BER.