Abstract: A maskless patterning apparatus allows for laser beam ablation of one or more layers of material while not etching an underlying different material layer. A micromirror array produces the desired complex pattern on the workpiece and a continuous feature and end point detection system provides location and material parameter changes to accurately control the pattern position and depth of etching. End point detection includes monitoring energy reflected from a specially prepared replica of the material to be ablated, whose thickness and consistency match the active workpiece area. The process terminates when the proper amount of material is removed.

Abstract: There is provided a system and method for ablating a surface of a work-piece comprising a radiation source for providing an ablating beam and a plurality of adjustable reflective masks having predetermined mask patterns thereon. The reflective masks are sequentially positioned relative to said radiation source and in the path of said ablating beam for reflecting said ablating beam onto the surface of the work-piece to ablate the work-piece.

Abstract: A method for making accurate and precise customized corrections to the surface of an optical lens is described. An electronic correction contour is generated from a measured refractive correction for a patient, and transferred to the surface of the lens by ablation etching with one or more laser pulses. After each of the laser pulses, the refractive properties of the lens are measured and compared to the electronic contour correction derived from a patient's refractive correction. The ablation etching is terminated in localized areas where the refractive properties match the electronic correction contour. End point detection includes monitoring refractive qualities of the lens during the recontouring process, modifying the pattern through changes in the laser pulses.