OPTICAL-TESTING OF A MACHINED MIRROR BY A COMPUTER-GENERATED HOLOGRAMINTERFEROMETER

Manufacturing technique for higher precision computer generated hologr ams has been developed. By calibrating and correcting the positional e rrors of a graphic plotter and the primary distortion of a photographi c lens, productions of higher accuracy holograms have become possible. Holograms of wavefront errors less than 1/40 wavelength have been ach ieved by this technique. Productions of a computer generated hologram for reconstructing helical wavefronts was demonstrated. Optical testin g of a machined surface was also demonstrated using a Twyman-Green int erferometer with the hologram.