A method of photoaltering a material using a puised laser beam includes selectinga first pulse energy and a first focal point separation based on a relationshipof pulse energy and focal point separation combinations enabling layer separationof the material by photoalteration, and scanning the pulsed laser beam alonga scan region at the first pulse energy and the first focal point separation. Therelationship has a slope and has a distinct change in the slope. The distinct changein the slope is associated with a second pulse energy of the relationship, andthe first puise energy is equal to or less than the second pulse energy.
