Methods and apparatus for treatment, such as
skin rejuvenation treatment, using non-uniform
laser radiation. A high-intensity portion of the
laser radiation causes collagen destruction and shrinkage within select portions of the treatment area, while a lower-intensity portion of the
radiation causes
fibroblast stimulation leading to collagen production across other portions of the treatment area. An output beam from a
laser source, such as an Nd:YAG laser, is coupled into an optical
system that -modifies the beam to provide a large-
diameter beam having a non-uniform energy profile, comprised of a plurality of high-intensity zones surrounded by lower-intensity zones within the treatment beam. The higher-intensity zones heat select portions of the
target tissue to temperatures sufficient for a first treatment (e.g. collagen shrinkage), while the lower-intensity zones provide sufficient energy for a second treatment (e.g. stimulated collagen production). A large area of tissue, preferably 7-10 mm in
diameter, can be treated simultaneously, while minimizing the risk of burning or other damage to the
skin. In one embodiment, the invention uses a
fiber bundle to provide a non-uniform energy output beam. In another embodiment, the invention uses a
diffractive lens array to produce the non-uniform output beam. A cooling
system can also be integrated with the
laser treatment system.