Nonlinear amplification and compression of envelope solitons by localized nonstationary parametric pumping

Amplification of envelope solitons by localized parametric pumping has been investigated. The possibility of extremely large single-soliton amplification (above the theoretical limit for an ideal linear amplifier) due to signal compression is predicted theoretically and demonstrated experimentally for backward volume magnetostatic waves in yttrium–iron–garnet films. In the case of a strongly localized nonstationary pumping signal, compression occurs due to the amplification of a part of the signal. In the case of a quasiuniform parametric pumping signal compression results from the development of collective oscillations of parametrically coupled spin waves. A single-soliton amplification gain of 17 dB has been obtained experimentally.