Influence of processing parameters and of natural ageing on the depth of a disturbed layer and on the optical strength of the surface of KCl single crystals

A study was made of the influence of the dimensions of abrasive grains and of the nature of the lubricating and cooling liquid during grinding, annealing, and natural ageing of polished surfaces of KCl single crystals on the depth of a disturbed layer and on the surface optical strength. It was found that the use of processing methods ensuring the minimum depth of the disturbed layer (for example, annealing) made it possible to increase considerably the optical strength compared with that obtained by traditional methods of processing of freshly polished or aged surfaces.