Aspheric Surface Measurement Based on Infrared Laser Interferometer

Here, a novel method for measuring an aspheric surface using an infrared laser interferometer is proposed. The model is divided into three modules. First, the wave front aberration between the aspheric surface and the standard spherical surface was measured by an infrared laser interferometer. Then, the theoretical value of the wave image difference between the aspheric surface and the standard spherical surface was calculated according to the aspheric equation. Finally, the surface shape deviation of the aspheric surface was calculated. To verify the validity and reliability of this method, the surface shape error of the same paraboloidal mirror was measured using the ZYGO visible light interferometer and the compensation mirror method. The obtained results indicate that these two measurement methods were identical. Hence, the novel method is convenient, fast, and highly versatile and can be used to test aspheric surfaces during processing.