High repetition rate laser restoration and monitoring of large area gilded surfaces

Abstract

Laser ablation of large surfaces requires a significant increase in the pulse repetition rate, fast and precise scanning of the laser beam and fast feedback control over the ablated surface layers. Here laser-induced breakdown spectroscopy(LIBS) as a diagnostic tool is combined with fast (up to 20 m.s-1) laser beam scanning over large surface areas in 250 kHz repetition rate laser ablation experiments. The experiments were conducted on samples of gilded surfaces painted over with raw umber acrylic and brass-based (with shellac medium) paints, and monitored by LIBS with the aim of removing the overpainting vv:ithout damaging the gilding. The successful integration of in situ spectral line radiation measurements \v:ith fast scanning expands the capabilities of the technique to high throughput industrial-scale laser ablation, laser deposition of films and precise laser treatment of large surface areas. Show more