Study of the optimum pulse-width of clock signal in optical and gates for application in ultra-fast OTDM networks

In this paper we study the effect of the clock signal's pulse width on the bit error rate (BER) of optical time division multiplexing (OTDM) networks. The receiver is considered to have a non-ideal optical clock recovery and, therefore, there is a time mismatch between the clock and data signals, which is called phase error. In this work, the phase error is modeled as a zero mean Gaussian random variable. Using this model, and considering Gaussian pulses for the data and clock signals, the BER of the receiver is calculated analytically. In numerical results, the BER is plotted versus the pulse width of the clock signal for different phase errors, and also for various bit intervals. Finally, the system is simulated and compared with the analytical results and an optimum value for the pulse width of the clock signal is obtained.