Generation of the high-order Bessel Beams by diffractive phase elements

We propose to apply the scheme of beam shaping for producing the high-order Bessel beams. In order to generate the ideal nondiffracting beams, two diffractive phase elements (DPE's) are required. The first DPE placed on the input plane of the beam shaping optical system is used to convert the incident wave into the output beam with the profile of a specified high-order Bessel function. The second DPE is placed on the output plane and serves as the phase corrector and compensator. The conjugate gradient method is employed to design these DPE's. Numerical results show that the designed DPE's can satisfactorily produce the high-order Bessel beams.