Negative Axicon Research Articles

The sensitive control on the cone angle of hollow beams

The sensitive control on the cone angle of hollow beams was studied in this paper, and the control system consists of positive, negative axicons and telescope zoom system. By analyzing, the condition of sensitive control on the cone angle was obtained. The curve of the cone angle variety against the element shift was given, and the theory we proposed is proved to be correct completely based on experiments. The research of sensitive control on the cone angle can provide a solid foundation in the fields such as fast scan-imaging and remote control etc.

Properties of Bessel beams generated by periodic gratings of circular symmetry

We show that the transmission of a periodic grating with circular symmetry can be composed of the sum of the transmissions of positive and negative axicons of different orders. The properties of the light beams generated by the gratings can be understood from the well-known properties of the light beam of an axicon, which is approximately a Bessel beam of zeroth order. The method is applied to a circular binary phase grating, which is investigated both theoretically and experimentally in the spatial domain and the Fourier domain. A simple and accurate method for determining the focal length of a lens with use of Bessel light beams is presented.