ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Microwave magnetic wave packets propagating in thin yttrium–iron–garnet (YIG) films show potential for novel devices as well as improved understanding of the basic properties of linear and nonlinear waves. The propagation characteristics of these excitations that have been studied up to now, however, do not provide a clear separation between linear and soliton regimes or a clear separation of the different contributions to the decay during propagation. The objective of this work was to study such characteristics for 5 GHz, 13–40 ns wide backward volume wave (BVW) magnetostatic wave square pulses in both the low-power linear and in the high-power soliton regimes and address these issues. The measurements were made with a delay time structure with a long and narrow 7.2 μm thick YIG film and 50 μm wide transducers, and input powers from 5 mW to 2 W. The output peak power Pout versus input pulse power Pin exhibits the same nonlinear response reported previously,1 with a linear response region A followed by a region B response with a more rapid increase in Pout and a high power region C in which Pout goes through a maximum and decreases. However, the integrated output pulse power, or pulse energy, is a strictly linear function of input pulse power over both the A and the B regions. At the same time, one finds a small but measurable increase in the average propagation velocity for the pulses as power is increased. The measured decay in the total pulse energy with propagation time leads to an unambiguous separation of the decay contributions due to dispersion and loss. This allows, in turn, a clear separation between the linear pulse and soliton regimes. The results were modeled from the nonlinear Schrödinger (NLS) equation with propagation and damping terms included. Agreement is good for regions A and B but the NLS model fails completely for region C.© 1997 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.364865
