The use of nematic liquid crystals in detection of polished glass surfaces defects

The thin layer of homogeneously oriented nematic liquid crystal (NLC) applied on an optical polished glass surface as a free film may visualise through a polarising microscope cleaning defects, local physical and chemical modifications of the surface and local relief defects. On this basis a new method to study different types of polished surfaces has been developed. The first results obtained are described.