JOURNAL OF MODERN OPTICS, vol.45, no.12, pp.2533-2539, 1998 (Journal Indexed in SCI)
The increase of signal power through an optical amplifier generally depends on the shape of the input signal. The optimum signal beam profile in three-level amplifiers is analytically determined using a variational approach. For a Gaussian pump distribution, it is demonstrated that a high-order super-Gaussian signal is nearly optimum for a wide range of the signal to pump width ratio.