Laser Cleaning of Paper-Based Documents

In recent years, laser technologies have been increasingly used in the restoration of cultural and historical heritage objects. One of the main applications of lasers in this field is the cleaning of objects from biological and anthropogenic contaminants. Compared to mechanical and chemical methods traditionally used in restoration over many years, laser cleaning technology offers several important advantages, such as high efficiency, delicacy, precision, and speed of contaminant removal. At present, laser cleaning is most developed for artworks made of stone and metal, while the laser cleaning of books and paper-based documents is still under investigation. Since paper is one of the most widely used materials in the creation of objects of global cultural and historical heritage, preserving and transmitting human knowledge across generations, research aimed at developing paper restoration methods is a significant and relevant scientific challenge. To date, laser cleaning has already shown positive results in the removal of various types of contaminants, such as dust, microfungi, and foxing. However, a unified, universal cleaning technology for books and paper-based documents has yet to be developed. This work presents experimental results on the laser cleaning of model samples and actual artifacts using a ytterbium fiber laser with a wavelength of 1.06 μm, along with studies of the paper properties before and after laser treatment.