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Experiment results of the effect of 3-regioned MRSZP (including two starting zones) with different starting zones according to Table 1 on the focal intensity pattern
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Multi-regioned square zone plate is presented which is achieved by sectioning a square zone plate into several regions. Each region is composed of Fresnel zones in a way that the first zone of a given region is the same as the last zone of the previous ones, from transmission point of view. By numerical studies and experimental works, we show capab...
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This paper presents a novel family of modular flat-foldable rigid plate structures composed by assemblies of 4R-linkages. First in the field of foldable plates, the proposed system is characterized by being not only foldable but also transformable: the slope of one module over the other is capable of changing not only magnitude but also sign. This...
Citations
... Hence, some techniques were proposed to improve its efficiency [16,17]. Furthermore, there have been reported some applications of SZP in, for example, infrared detectors [18], Cassegrain concentrator [19], solar energy systems [20], rectangle multi-array focusing [21], and unique rectangle array of structured beam [22]. ...
Herein, we are about to introduce a novel, reliable and straightforward method to create controllable dark lines employing an azimuthal square zone plate. As a matter of fact, this diffractive element is a square zone plate whose zones are phase-shifted azimuthally. As we illustrate, one way to construct it is combining a square zone plate and radial grating having period m. Considering its focusing behavior, we came to the result that a dark line surrounded by linear bright zones is generated for odd m, as well as a cross-like dark zone is produced when m is even. Furthermore, we illustrate that the length of the dark lines depends on the grating period. Finally, the simulation predictions are verified by experimental results.
Herein, we are about to introduce a novel, reliable and straightforward method to create controllable dark lines employing an azimuthal square zone plate. As a matter of fact, this diffractive element is a square zone plate whose zones are phase-shifted azimuthally. As we illustrate, one way to construct it is combining a square zone plate and radial grating having period m. Considering its focusing behavior, we came to the result that a dark line surrounded by linear bright zones is generated for odd m, as well as a cross-like dark zone is produced when m is even. Furthermore, we illustrate that the length of the dark lines depends on the grating period. Finally, the simulation predictions are verified by experimental results.
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A modified square spiral zone plate (MSSZP) is proposed to generate a square optical vortex with an adjustable shape and position. A radial modulation ${r_0}$ r 0 adjusts the shape of the two-arms-cross pattern for the square vortex. The vertical modulation $a$ a and horizontal modulation $b$ b make the central position of the square vortex move along the vertical and horizontal directions, respectively. The vertical or horizontal moving distance is linearly related to $a$ a or $b$ b , respectively. The slope of the corresponding fitting line is equal to 1/2. Based on the sum of topological charges of the MSSZP and spiral phase plate, the topological charge of the corresponding generated square vortex follows a modulo-4 transmutation rule, which is satisfied by setting the appropriate ${r_0}$ r 0 . The method of constructing the MSSZP is illustrated. It is proved in the simulations and experiments that the MSSZP has the adjustable square vortex. The proposed zone plate is applicable for optical image processing, infrared antennas, and laser alignment systems.
Generalized composite aperiodic zone plates (GCAZPs) are proposed to generate clearer images at focal planes. The images can be produced by a target object at infinity based on a collimator. The proposed zone plate consists of the proposed radial zone plate (RZP), whose original radius is not zero, and the common aperiodic zone plate, which has the coincident first-order diffraction area and the same axial first-order diffraction intensity distribution. The GCAZPs are applicable for the other aperiodic zone plates. Moreover, the modulation transfer function curve of the GCAZP is basically above that of the corresponding common aperiodic zone plate. Compared with the common aperiodic zone plates, the GCAZPs have the foci with higher intensity and the images with higher contrast at the same focal planes. In addition, a GCAZP with an arbitrary size can be designed. The construction method of the GCAZP is illustrated in details. Furthermore, it has been also proved numerically and experimentally that the GCAZPs are used to generate the clearer images than the corresponding common aperiodic zone plates. The proposed zone plates are applicable to generate clear images and trap particles stably at multiple planes simultaneously.
We propose a general n-fractal aperiodic zone plate generating a beam with the first-order foci with more chosen positions. The construction method of the general n-fractal aperiodic zone plate can apply to many aperiodic zone plates, e.g. fractal, Thue-Morse and Fibonacci zone plates, and the general n-fractal aperiodic zone plates can generate more adjustable first-order foci. Parameters of the n-fractal aperiodic zone plate such as the substitution rule and the fractal order are examined and found not to affect the fractal distribution of the first-order foci. The more adjustable first-order foci generated by the general n-fractal aperiodic zone plate have been verified with both simulations and experiments.
A novel diffractive element is presented which is made through lateral phase shifted square zone plate bounded along horizontal and vertical axes via two perpendicular rectangle windows, respectively. We demonstrate that \textcolor{red}{under a given condition} the element is able to produce a square light beam at the focal plane. We have also elaborated that the produced square beam can be simply manipulated by an appropriate combination of the phase shifting parameter and bounded width. Experimental works verify the simulation results.
