How is laser penetration controlled?
May 16, 2012 2:27 AM Subscribe
How is a laser beam controlled so that it only penetrates a fixed distance into a soft material that it could normally pierce right through?
posted by Quillcards to Science & Nature (7 answers total)
In laser eye surgery, one of the ways to correct the lens shape is to first drill a series of holes a few microns deep in a circle at the front of the eye and lift the circle of perforated tissue (like separating a postage stamp from a sheet) and then using a laser to reshape the exposed surface.
After that, the circle is replaced and being very thin, it sticks to the newly formed shape beneath.
My question is, how is the laser controlled so that it only penetrates a few microns deep as it 'cuts out' the circle rather than the beam just penetrating further into the eye?