Efficient generation of nearly diffraction-free beams using an axicon

ZnSe axicon is used to efficiently generate approximations to diffraction-free Bessel function beams at λ = 10.6 μm. The central spot radius of ~ 170 μm generated when the axicon is illuminated by a plane wave is maintained for distances of up to 11 cm with sufficient laser power to allow drilling of plexiglass to be demonstrated.