The effects of wave front reversal and inversion of the time profile are observed experimentally for a dipolar spin wave pulse (carrier frequency ${\omega }_1$) interacting in a yttrium-iron garnet film with a weakly localized nonstationary parametric pumping (carrier frequency ${\omega }_p\cong 2{\omega }_1$) in a three-wave process with conservation law ${\omega }_p={\omega }_1+{\omega }_2$, where ${\omega }_2$ is the carrier frequency of the reversed pulse. Theoretical analysis based on the solution of the system of equations for envelopes of interacting wave packets by means of a Green's function formalism gives a quantitative description of the observed phenomena.

• Received 6 October 1999

DOI:https://doi.org/10.1103/PhysRevLett.84.3438