Method and laser system for production of high-resolution laser-induced damage images inside transparent materials by generating small etch points

摘要

A method and apparatus for production of high-resolution laser-induced damage images by small etch points is based on generation of the initial electron density in the relatively large volume, creation of the breakdown at a small part of the said volume and control of the energy amount enclosed inside the plasma. The method uses two laser radiations: the first has comparatively long pulse width, its energy does not exceed damage threshold value, and it is focused at relatively large focal spot; the second has shorter pulse duration, it is focused at smaller spot and its energy exceeds appropriate threshold value. The system produces laser-induced damage images by joint using of an optical scanner (deflector) and a drive table for movement of article. The system works without interruption of article movement relative to the laser beam and creates image areas with different brightness by modulation of article replacement speed and frequency of scanning.