Phase-shifted Fresnel axicon

We propose an optical element: a phase-shifted Fresnel axicon for generation of multiple Bessel beams. By giving a binary phase modulation to the standard Fresnel axicon, the proposed element is generated. The phase profile of the binary phase modulation is engineered to generate two and three Bessel beams of equal intensities. This composite optical element is fabricated using electron beam direct writing. The performance of the fabricated device is evaluated using a semiconductor laser, and the generation of two and three Bessel beams is successfully demon-strated. © 2012 Optical Society of America OCIS codes: 050.1965, 050.1970, 220.4000. An axicon lens can be thought of as a rotationally sym-metric prism with a very large depth of focus [1,2]. Ax-icon lenses are widely used in beam shaping [3], optical trapping [4], laser machining [5], and so on. These many useful applications of axicon lenses have led to a rapid development in techniques for their design, fabrication, and implementation [6–8]. A technique for generating multiple identical Bessel beams for optical interconnec