Measuring Optical Purity Precisely
In order to determine the optical quality of laser optics, the Laser Zentrum Hannover e.V. (LZH) has developed a laser calorimeter which is able to measure the absorption of light in the material.
During the production of functional laser optics as well as for the development of innovative products in the optics industry it is necessary to precisely determine the purity of optical materials. The need for preciseness and sensitivity has increased extremely, especially for optimized materials of high quality. These materials include various quartz glasses, crystals and numerous other optical glasses, which also serve as carrier materials for quality coatings.
In order to determine the optical quality of laser optics, the Laser Zentrum Hannover e.V. (LZH) has developed a laser calorimeter which is able to measure the absorption of light in the material. Specific advantages of the device are its high sensitivity, absolute calibration and a wide spectral range of the test wavelength.
By using a precise temperature measurement of the material, the laser calorimeter is able to detect an absolute absorption of <1 ppm (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 193 nm and 2000 nm are possible. In addition, the range between 670 nm and 2200 nm is completely accessible. Measured data can be used to optimize the material, machining and coating processes. Thus, continuous improvement of respective characteristics of laser optics is possible.
The laser calorimeter is industrially available at the LZH in customer-specific versions. Also, the LZH offers services for absorption measurements for a great variety of laser beam sources for various industrial applications.
Source: Laser Zentrum Hannover (LZH)