Effects and elimination method of thermal radiation interference on reflectivity measurement

In the process of measuring the reflectivity from material surface, the thermal radiation of the material irradiated by laser usually brings obvious interference on the measurement, thus introducing a large measurement error. The measurement accuracy of the reflectivity of the high temperature section can be greatly improved by following procedure: a detector whose transmitting wavelength is different from the loading laser’s wavelength is added first, thus the light strength signal of the thermal radiation at the laser loading section and the temperature dropping section after the laser stops is detected, and at last a comparison method is adopted to eliminate the thermal radiation interference in the process of reflectivity measurement．