Fiber optics for Raman scattering at low temperatures and high-magnetic fields

A versatile and compact fiber-optic system for Raman scattering and photoluminescence is described. This optical fiber system was used for inelastic light-scattering experiments at temperatures down to T=0.35 K and dc magnetic fields to B=30 T. We believe this is the first observation of Raman scattering in either of these environments, both of which are normally inaccessible with optical Dewars. The portable head has a 1-cm o.d. and permits measurements longitudinal and transverse to the applied magnetic field. Observation of spin-flip Raman scattering from donor bound magnetic polarons in (Cd, Mn)Se demonstrates this system at the extremes of both magnetic field and temperature.