A polychromator implemented in reflection interference filters is desc
ribed. The polychromator is intended for analyzing the Thomson scatter
ing of laser radiation by hot plasma and has a contrast of more than 1
0(8). An important property of the instrument is that it utilizes the
input radiation almost completely. In an experimental study of plasma
with a high electron temperature (similar to 1 keV), the instrument pr
oved to be easy to handle and to produce reliable readings.