A new scheme for heterodyne polarimetry with high temporal resolution

A new scheme for making combined interferometric and polarimetric measurements on tokamak plasmas with high temporal resolution is presented. The method, which can be regarded as a generalization of techniques suggested by other workers, can achieve bandwidths in excess of 100 kHz using an optically pumped far-infrared triple laser source. A bandwidth of 10 kHz with an accuracy of better than 0.20 has already been demonstrated. Calibration measurements as well as first plasma measurements obtained with the new approach are presented and evaluated.