Focusing properties of spiral zone plate based on m-bonacci sequence

We propose a methodology for producing twin equal-intensity optical vortices with the same topological charge along the propagation direction by combining m-bonacci sequence with the spiral zone plates in the squared radial coordinate. Based on the Fresnel diffraction theory, the focusing property of such optics was analyzed and experimental demonstration was performed to verify its effectiveness. The results reveal that such optics may bring new opportunity and profit for plane optical trapping, optical micromachining, and confocal microscopy.