Performance evaluation of optical carrier suppressed RZ-DPSK signal in WDM networks employing OFC

A new arrangement of optical frequency comb and its deployment in a wavelength division multiplexed optical network is proposed and demonstrated. The generated optical carriers are separated by a frequency spacing of 10GHz and the overall spectra comprise 63 individual optical carriers. These carriers are identified and separated by utilizing rectangle optical filters, and 10Gbps data is modulated on each carrier frequency. The data is modulated using carrier suppressed return to zero differential phase-shift keying (CSRZ-DPSK) modulation technique. Furthermore, the performance analysis of DPSK and CSRZ-DPSK (presuppressed RZ-DPSK, postsuppressed RZ-DPSK, and suppression of multiplexed DPSK signal) are studied in details. In our analysis, it is observed that the three suppression techniques produce almost the same level of suppression, however, the bit error rate and Q factor differ. It has been observed that the postsuppressed DPSK modulation scheme offers more tolerance towards chromatic dispersion and other fiber impairments and nonlinearities such as self-phase modulation and offers better overall performance. The results are analyzed in terms of BER performance, Q-factor, and eye-opening penalty.