A method for measuring the base angle of axicon lens based on chromatic dispersion

A method for measuring the base angle of axicon lens is presented. This method utilizes two coaxial laser beams with different wavelengths. When the two laser beams passing through the axicon lens, there will be a small divergence angle between them resulted from chromatic dispersion. After collected by an achromatic lens, these two laser beams will generate two spots on an image camera. The base angle can be figured out with the distance between two spots recorded by the image sensor. Furthermore, this method can also be used to calculate the cone angle of axicon lens.