Measurement of base angle of an axicon lens based on auto-collimation optical path

摘要

Axicons are widely used in many applications because of their unique optical characteristics. In this paper, a new method for measuring the base angle of an axicon lens based on auto-collimation optical path is presented. When a laser beam is vertically incident on the flat surface of an axicon lens, it deflects after transmission. Auto-collimation is achieved when the transmitted light is reflected by a parallel plate. By recording the deflection angle of the parallel plate before and after the axicon lens is placed in the experimental configuration, the base angle of the axicon lens can be computed. A preliminary experimental validation is presented with a 20 degrees axicon lens. The measurement accuracy of the presented method can be better than 10 arcseconds.