Time and Space Resolved Brillouin Light Scattering (BLS) System - diagram

Brillouin light scattering (BLS) is a powerful technique for the study of both thermal and externally pumped microwave excitations in magnetic systems in general and thin films in particular. The above figure shows a schematic of the system at CSU. The main parts of this system include a Sandercock type (3+3) pass Tandem Fabry Perot Interferometer, an Ar ion laser, two separate electromagnet stations, Hillebrands control software and hardware, and a three-axis step motor driven sample scanning stage with micrometer step capability. For work on pumped excitations, the system includes microwave equipment for cw down to nanosecond pulse excitation of spin wave signals in magnetic films. The accessible range of thermal spin wave excitations for the BLS system is from a low limit of about 1 GHz to an upper limit close to 300 GHz. The system is computer controlled, user friendly. and set up for both back scattering and forward scattering experiments. Pumped excitations in transparent films studied in the forward scattering configuration can also be observed with time (1.7 ns) and space (0.1 mm) resolved capabilities. The forward scattering configuration is also wave vector selective, with a resolution down to 50 rad/cm.