Simple technique for testing deep aspherical surfaces

A simple method to measure the aspherical surface of test elements by immersing them in a liquid crystal container is presented. The theory of the method is given and the experimental results of two lenses, one made of a plane surface and a spherical surface and the other with a spherical surface and an aspherical surface, are demonstrated. (C) 1999 Society of Photo-Optical lnstrumentation Engineers. [S0091-3286(99)01704-3]