Axicons (conical lenses) are famous due ability to transform collimated Gaussian beam into approximation of non-difracting Bessel beam in the near-field and ring-shaped beam in the far-field. Most often they are used in tandem with other types of lenses. 4Lasers provide plano-convex and plano-concave design conical lenses. These lenses feature one convex surface or one concave conical surface, respectively, while second surfaces are plano in both cases.