Patent ID: 7585596

Claim:
A method for micro-sculpting in an optical image reduction machine comprising the steps of: selecting a photo-active material for fabricating a pre-selected micro-element; selecting a duty cycle that translates to image a desired variable analog optical intensity pattern as a height variation on a surface of the selected photo-active material, wherein a developed photo-active material depth is a nonlinear function of exposure; determining an analog intensity for a profile of the pre-selected micro-element; creating a binary pi phase grating photo-mask on a transparent reticle according to the profile of the pre-selected micro-element using the determined variation in duty cycle; providing a layer of the selected photo-active material on one single side of a target substrate; directly exposing said selected photo-active material on the one single side of the substrate by transmitting only one single radiation to said selected photo-active material through said pi phase grating photo-mask that transmits said radiation with a transmittance proportional to the period and duty cycle of said pi phase grating photo-mask to allow only a 0th order diffracted radiation from the pi phase grating photo-mask with a pi phase shift to control an optical transmittance by varying the duty cycle of the phase grating to develop said selected photo-active material; and processing said selected photo-active material to form the variable intensity pattern in said developed photo-active material that corresponds to the optical transmittance of said pi phase grating photo-mask.