Embodiments of methods and an apparatus for creating points or areas of
laser-induced damage inside a transparent material are disclosed. One or
more embodiments of the invention comprise a method and system for
producing etch points by control of breakdown process development. In one
embodiment, at the beginning an applied laser radiation level just exceeds
an energy threshold for creating a plasma condition in the material, and
thereafter the energy level of the applied laser radiation is just
maintain the plasma condition and is applied before the plasma condition
extinguishes, but after a shock wave associated therewith has passed.
Other embodiments of the invention comprise a method and a system for
producing etch points by controlling a space structure of laser beam.
According to the invention a laser generates a TEM.sub.mnm radiation. The
values of the integers m and n are controlled and determined so as to
reproduce particular gray shades for a particular point of an image.
Points or areas of laser-induced damage produced by these methods do have
the traditional and undesirable star configuration. Furthermore, it is
possible to control the brightness of these points without changing their
size.
