Method of manufacturing wave shaping objects

Abstract

Abstract THE TECHNIQUE IS FOR ARBITRARILY ALTERING A PHYSICAL (E.G., ELECTROMAGNETIC OR SOUND) WAVEFRONT, IN WHICH THE WAVEFRONT IS SHAPED BY MODIFYING ITS PHASE IN A CONTROLLED MANNER. A FIRST ASSUMPTION IS MADE THAT THE IMAGE TO BE FORMED IS OF AN OBJECT MADE UP OF POINT SOURCES WITH THE PHASES OF THE RAYS FROM EACH SOURCE BEING RANDOM. THE RANDOM PHASES ASSUMPTION PERMITS THE SECOND AND FURTHER ASSUMPTION THAT THE AMPLITUDE OF THE WAVEFRONT, INCIDENT ON A PLANE, IS CONSTANT. THEREFORE, THE WAVEFRONT IS SHAPED SOLELY BY OPERATING ON ITS PHASE. THE WAVEFRONT SCATTERED FROM AN OBJECT IS FIRST, IN THE PREFERRED EMBODIMENT, CALCULATED DIGITALLY AND THE CALCULATION IS IDENTICAL TO THAT USED TO CALCULATE THE WAVEFRONT AS IN CONVENTIONAL DIGITAL HOLOGRAPHY WHEN A POINT APERTURE OBJECT ASSUMPTION IS MADE. THE PHASE OF EACH POINT IN THE WAVEFRONT IS DETERMINED AND A PLOT TAPE WRITTEN FOR A PLOTTER, THE PHASE INFORMATION SCALED FROM 0 TO 2$ OVER THE GRAY LEVELS AVAILABLE, SUCH THAT A PHOTOGRAPHIC FILM IS PRODUCED, THE DARKENING OF WHICH OVER ITS AREA IS A MEASURED OF PHASE. THE THUS PRODUCED FILM IS THEN PHOTO-REDUCED TO GIVE A PHASE DISTRIBUTION AT THE APPROPRIATE WAVELENGTH OF LIGHT. THE PHOTO-REDUCTION IS THEN BLEACHED SUCH THAT THE EMULSION IS OF UNIFORM TRANSMISSIVITY BUT WITH AN ETCHED SURFACE, THE ETCH DEPTH OF WHICH IS PROPORTIONAL TO EMULSION DARKENING. UPON ILLUMINATION THE WAVES INCIDENT UPON THE PHOTO-REDUCTION ARE SELECTIVELY RETARDED BY THE THICKNESS DIFFERENCES OF THE EMULSION SUCH THAT THE RESULTANT INTERFERENCE AT AN IMAGE PLANE PRODUCES THE DESIRED IMAGE.

Inventors

• 👤 Peter M Hirsch
• 👤 James A Jordan Jr
• 👤 Louis B Lesem

Bibliographic Details