High-purity glasses based on arsenic chalcogenides

Low impurity content is the essential requirement to many applications of vitreous arsenic chalcogenides as a material for optoelectronics. Investigations carried out in last ten years in-creased the knowledge volume about the nature and origin of impurities in chalcogenide glasses, their effect on glass properties, especially on the transmittance in middle IR region and on radiation strength. These properties are most sensitive to impurity presence. The mini-mum calculated content of impurities, leading to observation of impurity contribution to the property value, is 0.1- 100 ppb at. for different impurity groups. The effective methods of preparations and analysis of high- purity glasses are developed. The best glass samples con-tain the impurities of widespread metals and silicon on the level of 0.1 ppm wt., optically ac-tive hydrogen- 0.2-0.05 ppm at., oxygen and carbon- 0.5- 1 ppm wt., submicron size het-erogeneous inclusions- 104- 5*106 cm-3. Impurity content in the glasses of ordinary quality is 10- 100 times higher. The presence of impurities should be taken into account while investi-gating both well-known and developed properties and applications of glasses