Patent ID: 6618174
Filing Date: 2003-09-09
Classification: B23K,G02B,G03F,G03H,Y10S

Abstract:
A method of imparting an image to a workpiece comprising the steps of:a) forming an in-line holographic mask by; a1) providing an object mask, a recording medium, and a first source of illumination, said object mask having a first side, said recording medium having a first face; a2) providing illumination from said first source of illumination to said first side to generate object waves incident on said first face; a3) using illumination from said first source of illumination to generate reference waves incident on said first face so as to interfere with said object waves incident on said first face, wherein said object mask does not shadow said central region of said recording medium from reference waves; a4) recording an interference pattern of said interfering waves in said recording medium; b) providing a second source of illumination for generating a reconstruction beam, said reconstruction beam having a reconstruction beam wavelength and reconstruction beam fluence; c) providing a workpiece; and d) illuminating said recording of said interference pattern with said reconstruction beam so as to impart a real image to the workpiece, wherein said reconstruction beam has a wavelength different from the wavelength of said illumination in said step (a2) and (a3).