Double-helix array structure using phase controlled interference of 6+6 beams

We describe a novel single-step approach to form hexagonal array of DNA like intertwined double-helix structure. The lattice structure has been simulated by using interference of 6+6 mutually counter-propagating beams arranged in a double-cone geometry. This is a phase controlled interference technique where each of the twelve beams is assigned a suitable phase offset and the helicity of the double-helix structure depends on the phase offsets of the interfering beams. For the application of the structure as a broadband circular polarizer, a simulation study has been performed using standard FDTD (finite difference time domain) method. A comparative study between aluminium(Al) based single-helix and double-helix hexagonal lattice structures is also carried out, showing that the operating wavelength range of the double-helix structure is much larger as compared to the single-helix structure.