A novel method of measuring convex aspheric lens using hologram optical elements

In order to simplify the complexity and improve the accuracy of convex aspheric lens testing, a novel method is proposed in this paper. In this method, convex aspheric lens is tested in transmitted light at the design wavelength by means of a Mach-Zehnder interferometer. Lens under test and its collimating lens are situated in one arm of Mach-Zehnder interferometer, Hologram Optical Elements (HOEs) acting as the compensator is placed in the proper position in another arm of interferometer. The principle of this setup is analyzed. The design and manufacture of HOEs and spatial filter used in this method are described in detail. In comparison with other methods, the advantages using this method are: (1) complex compensation lenses are not required any more, which simplifies the compensating structure and decreases the costs of measurement, (2) HOEs is easier to be fabricated. A convex-plane aspheric lens as an example is experimented.