Wavefront phase measurement of striae in optical glass

We present a method for evaluating the quality of optical glass using a high-resolution wavefront sensor, the wavefront phase imaging (WFPI) sensor. As shadowgraphy is a widely used method for inspecting striae in optical glass, it does not provide a quantitative metric that represents the potential optical quality of the glass and should be based on the operator's experience. We compare the proposed method in two experiments. First, we compare it with the results obtained by shadowgraphy on a variety of samples. Second, we compare the results of a single-point chromatic confocal profilometer on a calibrated sample. The WFPI shows results comparable to the reference method in both cases but provides more information than shadowgraphy and avoids the human factor in the measurement. (C) 2022 Optica Publishing Group under the terms of the Optice Open Access Publishing Agreement

Automated summary

This paper presents a method for evaluating the quality of optical glass using a high-resolution wavefront sensor and compares it with the commonly used shadowgraphy method. The results show that the proposed method is comparable to the reference method and provides more information while avoiding the human factor in the measurement.