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 amplificat ion (above the theoretical limit for an ideal linear amplifier) due to sign al compression is predicted theoretically and demonstrated experimentally f or backward volume magnetostatic waves in yttrium-iron-garnet films. In the case of a strongly localized nonstationary pumping signal, compression occ urs due to the amplification of a part of the signal. In the case of a quas iuniform 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. (C) 2 001 American Institute of Physics.