INVESTIGATION OF INSTABILITIES OF A PERPENDICULARLY PUMPED YTTRIUM IRON GARNET WITH THE AID OF A LASER BEAM.

A laser beam of wavelength lambda equals 1. 15 mu was used to investigate instabilities of first ( omega //k equals omega //0/2) and second ( omega //k equals omega //0) order under perpendicular pumping at a frequency 1. 1 GHz. The investigations were performed for an yttrium iron garnet measuring 3 multiplied by 3 multiplied by 10 mm. The alternating component of the magnetization m and the change DELTA M of the dc component of the magnetization were determined, as were the regions of magnetic fields in which the instabilities are observed. The results are compared with an investigation of the diffraction of laser radiation by magnetostatic and magnetoelastic waves.