A surface-spin-wave interferometer

The design and operation of an iron-yttrium garnet interferometer for measuring the dispersion of surface magnetostatic waves are described. Typical interferograms obtained with the device proposed here are presented. It is shown that for low wave numbers, when the efficiencies of excitation and reception of surface magnetostatic waves are sufficiently high, the signal is nearly harmonic. As the wave number increases, the efficiencies of wave excitation and reception decrease, resulting in increased error. The error can be reduced by using a high-stability magnet power supply and special attachments at the magnet poles. In the experiments reported here the error did not exceed 5 percent.