METHODS AND SYSTEMS FOR LASER TREATMENT USING NON-UNIFORM OUTPUT BEAM
Methods and apparatus for treatment, such as skin rejuvenation treatment, use 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 nonuniform 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, hi 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. A pulse light source can also be integrated with the laser treatment system in a combined skin rejuvenation therapy.