Experimental study of wavefront distortion in the dark hollow beam generated using axicon

Axicons are the optical components widely used for the generation of dark hollow beam in a controlled manner. In certain circumstances, distortion in the transverse intensity profile (i.e. wavefront distortion) appears in DHB produced by axicon-lens assembly. In this paper, we performed the detailed experimental study for exploring the reasons for the appearance of wavefront distortion including its control and removal in partially coherent dark hollow beam produced from axicon-lens assembly. This experimental study find its crucial importance in the applications, where axicon is used for producing dark hollow beams, e.g. in eye surgery, atom trapping, laser machining and laser resonator. We also observed that the effect of chromatic aberration near the region of induced wavefront distortion in the depth of focus changes with propagation and can be controlled by varying spatial coherence of the beam. This control on the effect of chromatic aberration will be helpful in attaining achromatic dark hollow beam from axicon.