Equilateral hyperbolic moir� zone plates with variable focus obtained by rotations

Abstract

We present equilateral hyperbolic zone plates with variable focal length, which are formed as moiré patterns by a mutual rotation of two identical basic grids. Among others, all principal zone plates, except of the spherical one, can be used as these basic transmittances. Three most important advantages of the proposed moiré zone plates are: a constant aperture of the created element during the mutual movement of basic grids, lack of aberrations due to their undesired mutual lateral displacements and high diffraction efficiency of the binary phase version. To obtain clearer moiré fringe pattern, a radial carrier frequency can be added additionally to the transmittances of basic grids. The destructive interference between both arms of the focal cross of the equilateral hyperbolic moiré zone plate can be obtained by a constant phase shift introduced in the transmittances of the basic grids. Potential applications of discussed elements are indicated, including the most promising one in the three-point alignment technique.

Diffractive performance of square Fresnel zone plates

“…Also four small lobes at the diagonals are observed. The cross-like pattern has been observed previously [8], [9], [10], [11].…”

“…In some designs, circular symmetry is not used, as those based on hyperbolic contours or shapes. These designs show interesting properties and allow new uses [8][9] [10]. Also a square FZP has been proposed as a combination of cylindrical FZP [11].…”

Reconfigurable continuous-zoom metalens in visible band

“…Recently, researchers have proposed the Moiré effect [24,25] combined with diffractive optical elements (DOEs) to realize zooming by relatively rotating two DOEs [26,27]. In this paper, we further verify that the Moiré effect can be realized by the combination of two chiral GEMSs and they can be used to form a continuous-zoom metalens.…”

Principles, Functions, and Applications of Optical Meta‐Lens

“…[ 147,148 ] A derivative of the Alvarez system is also presented where the two lenses are coaxially rotated rather than being parallelly moved, which is inspired by the Moiré lens. [ 149–153 ] Cui et al. [ 151 ] proposed a rotationally tunable polarization‐dependent varifocal metasurface, and Yilmaz et al.…”

“…[147,148] A derivative of the Alvarez system is also presented where the two lenses are coaxially rotated rather than being parallelly moved, which is inspired by the Moiré lens. [149][150][151][152][153] Cui et al [151] proposed a rotationally tunable polarization-dependent varifocal metasurface, and Yilmaz et al [152] demonstrated a polarizationindependent varifocal metasurface. Subsequently, Guo et al [153] fabricated a 3.5× continuous varifocal meta-lens in the microwave band, with an improved N.A.…”