Effect of a Raman co-pump's RIN on the BER for signal transmission using ON-OFF keying modulation format

This paper theoretically studies the effect of the relative intensity noise (RIN), which is transferred to the signal from a Raman co-pump, on the bit-error rate (BER). We show that a given amount of the transferred RIN degrades the BER by about an order of magnitude more than does the same amount of the amplified spontaneous emission (ASE) added to the signal. We investigate how this effect depends on such parameters as the duty ratio of the signal pulses and on the amount of the ASE that has been added to the output signal along the transmission line.