Microwave Solitons and Precessional Dynamics in Magnetic Thin Films - Physics and Devices

摘要

There were two focus areas in the original proposal, (I) soliton and short pulse phenomena in ferrite films and (II) linear and nonlinear wave propagation in metallic ferromagnetic films and structures. Under I, considerable effort was devoted to the problem of loss and decay that limits soliton and short pulse phenomena for signal processing and communications and other devices important for Army applications. New results on nonlinear damping, high power foldover, and higher order soliton formation and production were also obtained. New results on soliton trains through modulational instability and recurrence processes were also realized. Under II, progress was made in the characterization of high power microwave and spin wave instability processes in Permalloy films. The one year overlap between this program and the new ARO MURI program on GHz Electromagnetic Wave Science and Devices for Advanced Battlefield Communications, in which Colorado State University is a major participant, allowed for new work as well. This includes the development of active feedback rings for broadband chaotic signal generation in YIG, work on the use of parametric pumping to trap and clone short spin wave pulses, and the production of soliton fractal signals. This work is ongoing under the new MURI program.