Millimeter-wave beam shaping using holograms

Pseudo-Bessel Beams in Millimeter and Sub-Millimeter Range

“…However, at millimeter and sub-millimeter wavebands, only two methods of production Bessel beams have been proposed currently, i.e., axicon (Monk et al, 1999) and computer-generated amplitude holograms (Salo et al, 2001;Meltaus et al, 2003). Although the method of using axicon is very simple, only a zero-order Bessel beam can be generated.…”

“…To overcome these problems, binary axicons, based on binary optical ideas, are introduced in our study and designed for producing pseudo-Bessel beams at submillimter wavelengths. The designed binary axicons are more convenient to fabricate than holographic axicons (Meltaus et al, 2003;Courtial et al, 2006) and, become thinner and less lossy in the material than classical cone axicons (Monk et al, 1999;Trappe et al, 2005;Arlt & Dholakia, 2000). In order to analyze binary axicons accurately when illuminated by a plan wave in sub-millimter range, the rigorous electromagnetic analysis method, that is, a 2-D FDTD method for determining electromagnetic fields in the near region in conjunction with Stratton-Chu formulas for obtaining electromagnetic fields in the far region, is adopted in our work.…”

Quasi-Optical Bessel Resonator

“…Examples can be found in [7,8,[12][13][14][15][16]. To our knowledge, no active schemes have been reported at these wavebands as yet.…”

“…Numerous approaches to generate pseudo Bessel beams have been suggested, which can be sorted roughly into two classes [3][4][5], i.e., passive and active schemes. The first class uses the spatial filter to transform an incident beam into an approximation to Bessel beam, such as narrow annular slit [2], computer-generated holograms (CGHs) [6][7][8], Fabry-Perot cavity [9], optical refracting systems [10], axicon [11][12][13][14] and diffractive phase elements (DPEs) [15][16][17]. The other class is formed by methods relying on a resonator frame to produce the Bessel-type modes.…”

Properties of Approximate Bessel Beams at Millimeter Wavelengths Generated by Fractal Conical Lens

“…However, reasonably good approximations can be made. Currently, numerous approaches for generating Bessel beams have been proposed, such as axicons [4], computer-generated holograms (CGH's) [7,8] and diffractive optical elements (DOE's) [9], among which the simplest and easiest realization scheme is using axicons. Accordingly, much interest has been provoked in design and analysis of axicons [10], and the number of axicon applications has also increased significantly in the last few years [11].…”