RIN transfer analysis in pump depletion regime for Raman fibre amplifiers

Extreme statistics in Raman fiber amplifiers: From analytical description to experiments

“…This merely explains why the signal tails are asymptotically limited by the exponential pdf of the pump (Eq. 7) : saturation of the gain strongly reduces the probability of the most extreme amplification factors [22] and the pdf ultimately exhibits a linear decrease in semilogarithmic scale (when no spontaneous cascading of the Raman process occurs during the amplification). This study also shows that the tails of the pdf distributions may be controlled in practice.…”

“…Analytical expressions of the probability density functions of the signal intensity are calculated explicitly under certain conditions. Contrarily to the widely spread approach based on the relative intensity noise (RIN) derivation in the frequency domain [19][20][21][22][23], our results will be directly derived through an analysis in the temporal domain. Numerical simulations will confirm the trends obtained analytically.…”

“…With this discretization, the sampling of the random function ) (x η 'involves uncorrelated random variables' η i , which allows us to assume that the random variables η i are independent from each other. We shall now calculate the pdf of the random variable ∑ η , recalling that the pdf of η i is deduced from the pdf of P Because the random variables η i are independent, the pdf of R N is simply given by the product of N convolutions of ) ( i pdf η[22]. Such a convolution may easily be calculated in the Fourier domain by means of the corresponding characteristic functions[22].…”

Fiber Bragg gratings for dispersion compensation in optical communication systems

“…Co-pumped Raman amplifiers suffer from high relative intensity noise transfer from the pump [60,61], but give the lowest noise figure of the three pumping configurations due to high path average power. Recently, pump lasers with very low RIN have become available, so co-or bi-directional pumping has become practical.…”

Suppression of pump-to-Stokes relative intensity noise transfer in Raman fiber laser by injection of modulated signal

“…However, the previously reported RFLs maybe have high relative intensity noise (RIN) due to the RIN transfer from pump sources [2], which has undesirable effects if transferred to the signal amplified by RFAs. The situation is worsened since the RIN transfer function [3] is much larger than unity at low frequencies. Recently, a double-cavity structure [4] has been proposed to achieve a low-frequency RIN transfer suppressed RFL, but the low-noise output power may be unstable because it corresponds to the left cavity just above threshold.…”