Method and apparatus for analysis of schlieren

摘要

The method for evaluating schlieren in glassy or crystalline optical materials includes irradiating a test sample of the optical material with light and producing a shadow image of the test sample on a projection screen. The shadow image of the test sample is received in an electronic image receiving device, such as a digital camera, and is compared with another shadow image of schlieren obtained with a comparison sample by means of interferometry. Then the optical material of the test sample is evaluated with the help of the comparison results.