Abstract

When forging spherical or aspherical lenses, a large difference in the optical figures can be found between the forged lens surface and the diamond-turned die. A two-wavelength holographic technique can be used to test the forged lens surface when the resulting interferograms are too complicated to analyze. However, when the difference is small, or when an aspheric die is to be evaluated, another unique holographic technique is available which uses a computer generated hologram for the null optics. This paper describes these two holographic techniques for testing the forged ir optics at the visible wavelengths.

© 1980 Optical Society of America