Generation of Bessel beams at millimetre-wave frequencies by use of an axicon

摘要

An axicon is used to generate a Bessel beam at 90 GHz in the millimeter-wave region of the spectrum. The Bessel beam has a central maximum of approximately 4 mm in diameter that is maintained over a propagation distance greater than 60 mm. A Gaussian beam of the same wavelength has a Rayleigh range below 10 mm. This illustrates clearly the increased depth of field of a Bessel beam.