
The instantaneous PTF of the optical PA was obtained by replacing the ASE
source with a CW source at 1557 nm (pulsed source off). The relationship between
the input signal power and the output cascade power is shown in Figure 20.46.
Figure 20.47 shows the measured output average cascade power as a function of
changing OSNR [OSNR = 10 log
10
(S/N ), where S is the average power of the
pulsed signal without noise and N is the noise power in a 0.1-nm bandwidth
centered at the signal wavelength]. The average combined signal launch power
was kept constant at 0.27 mW, equivalent to a peak pulse power of 1.92 mW when
there was no ASE. The experimental results ...