Measurements of the ellipsometric parameters of optical components inside an active laser

A novel transmission ellipsometric measurement method with the component under test inside an active laser is presented. Analyzing frequency and polarization property of the laser radiation we can detect five ellipsometric parameters of the component under test. For the first time it is possible to distinguish between reciprocal and nonreciprocal optical rotation. The polarization properties of the laser are changed in a defined manner by two novel optical modulators. Our experiments using a diode-pumped Nd:YAG laser demonstrate the high accuracy and the short measurement time of the measurement method.