Generating approximate non-diffracting Bessel beams by using passive method

Bessel beams have received a wide number of applications in many fields, from metrology, classical optics to nonlinear optics and life science, owing to their special beams properties which the core of the beam is small and invariant propagation, self-healing and realized bottle beam。 The generation and transformation of the nondiffracting beam is an active research field nowadays。The propagation properties of the Bessel beam were described based on interferential theory, diffraction theory and geometrical optical theory。 The generation methods of nondiffracting Bessel beams can be divided into active and passive。 In this paper, three new passive generating methods have been given。 By analyzing the advantages and disadvantages of these generating methods, we proposed the scope of their applications。