AbstractA new method is presented for performing combined interferometric and polarimetric measurements on tokamak plasmas with high temporal resolution. The method can be regarded as a generalization of techniques suggested by others. A triple-laser far-infrared system serves to generate three frequency-offset laser beams, of which two are used to probe the plasma in orthogonal polarization states. The method has been implemented at the Rijnhuizen Tokamak Project. Some features of the method will be discussed and first plasma measurements will be presented.