We analyze the optical behavior of Square Fresnel Zones Plates. A theoretical analysis and numerical simulations based on the Rayleigh-Sommerfeld approach have been developed analyzing properties such as the depth of focus and the intensity of the focus in terms of the number of zones. In addition, an experimental verification has been performed using a Spatial Light Modulator to implement the ...

A novel fabrication process is proposed for manufacturing thin-film metal Fresnel lenses for X-ray applications. This process combines diamond turning technology and photolithographic processes. To prevent thin-film lens substrates from deflection during diamond turning, films were prepared on single crystalline silicon wafers by electrolytic plating. After the Fresnel lens structure is generat...

As has been discussed in main text, we use a designed initial guess derived from a mixture of a series of Fresnel lenses’ profiles for different wavelengths. Without loss of generality, we take an amplitude-type Fresnel zone-plate (FZP) as the instance for principle illustration. Leveraging scalar diffraction theory, the complex amplitude of a point at the image plane is the sum-up of all compl...

This paper presents a tuneable binary amplitude Fresnel lens produced by wafer-level microfabrication. The Fresnel lens is fabricated by encapsulating lithographically defined vertically aligned carbon nanotube (CNT) bundles inside a polydimethyl-siloxane (PDMS) layer. The composite lens material combines the excellent optical absorption properties of the CNT with the transparency and stretchab...

Fresnel zone plates are diffractive elements that are essential to form images in X-ray microscopy[1,2]. One of the main shortcomings of Fresnel zone plates their high chromatic aberration. Recently presented, Fractal Zone Plates (FZPs) [3] are diffractive lenses characterized by a fractal focal structure with an extended focal depth, as compared with Fresnel lenses. This behaviour predicts an ...

We present a proposal for a X-ray optical element suitable for X-ray microscopy and other X-ray-based display systems. Its principle is based on the Fresnel lenses condition and the Bragg condition for X– ray scattering on a slice of monocrystal. These conditions are fulfilled simultaneously due to a properly machined shape of the monocrystal with a stress at its ends.

Diffractive optics, such as Phase Fresnel Lenses (PFL’s), offer the potential to achieve excellent imaging performance in the x-ray and gamma-ray photon regimes. In principle, the angular resolution obtained with these devices can be diffraction limited. Furthermore, improvements in signal sensitivity can be achieved as virtually the entire flux incident on a lens can be concentrated onto a sma...

We realize homogenous luminance of the directional backlight for the time-division multiplexing autostereoscopic display using a convex lens array with the elemental lenses whose phase of placement in each row differs from one another. The validity of the proposed optical design is confirmed by a prototype system. key words: autostereoscopic display, homogeneous brightness, liner Fresnel lens a...

Aim: To determine any differences in visual acuity (VA) and contrast sensitivity (CS) between 3M Fresnel prisms and Trusetal prisms foils. Methods: Sixteen participants (mean age 20 years) with normal VA and CS participated. The effect of 5D, 10D, 20D and 30D prism strengths on monocular VA and CS was assessed using a Bailey-Lovie logMAR chart and Pelli-Robson chart, respectively. Measurements ...