Laser Zentrum Hannover has developed a laser calorimeter that can measure the absorption ot light in optical materials. It features high sensitivity, absolute calibration and a wide spectral range of test wavelength.
By using a precise temperature measurement of the material, the laser calorimeter is able to detect an absolute absorption of <1ppm (one millionth of the irradiated laser power). This preciseness can detect the smallest absorption data deriving from surfaces, coatings or impurities in the material. Absorption measurements with laser wavelengths between 193nm and 2,000nm are possible. In addition, the range between 670nm and 2,200nm is completely accessible. Measured data can be used to optimise the material, machining and coating processes. Thus, continuous improvement of respective characteristics of laser optics is possible.