Large signal analysis of FM-AM conversion in dispersive optical fibers for PCM systems including second order dispersion

By using large signal analysis for dispersive optical fiber, the FM-AM conversion with respect to binary intensity modulated PCM systems including second order dispersion term is discussed. The modified expression for power penalty has been derived and its impact on laser linewidth and bit rate has been investigated. For power penalty less than 0.5 dB, the plots between bit rate and transmission distance are plotted. It is seen that the transmission distance increases with decrease in linewidth over significant bit rates. The transmission distance with first order dispersion term for 300 MHz linewidth is approximately 800km. With proper first order dispersion compensation, i.e., with second order dispersion only, the transmission distance can be enhanced to 10 8 km for this linewidth. The linewidth requirements for systems with different bit rates and transmission distances are also calculated and discussed. Further, it is seen that by including the second-order dispersion term, the bit rate and transmission distance decreases. For higher linewidths, this decrease in bit rate and transmission distance is very less and vice versa. For 300 MHz linewidth, the decrease in transmission distance is just 30 km, and for 30 MHz linewidth, the decrease is approximately 600 km over significant bit rates.