نتایج جستجو برای: diffractive optical element

تعداد نتایج: 468384  

Journal: :Journal of the Optical Society of America. A, Optics, image science, and vision 2001
U Levy D Mendlovic E Marom

Multilevel diffractive optical elements are necessary for achieving high-efficiency performance. Here the diffraction efficiency of a multilevel phase-only diffractive lens is analyzed. Approximate, as well as more accurate, approaches are presented. Both plane-wave and Gaussian illumination are discussed. It is shown that for many practical cases the diffraction efficiency can be determined by...

Journal: :Optics express 2010
Mona Mihailescu

A naturally-inspired phase-only diffractive optical element with a circular symmetry given by a quasi-periodic structure of the phyllotaxis type is presented in this paper. It is generated starting with the characteristic parametric equations which are optimal for the golden angle interval. For some ideal geometrical parameters, the diffracted intensity distribution in near-field has a central ...

Journal: :Applied optics 2004
Mark S Mirotznik David M Pustai Dennis W Prather Joseph N Mait

We describe a design methodology for synthesizing polarization-sensitive diffractive optical elements based on two-dimensional form-birefringent microstructures. Our technique yields a single binary element capable of producing independent phase transformations for horizontally and vertically polarized illumination. We designed two elements for operation at 10.6 microm and fabricated them in si...

2001
Jason D. McKinney Dong-Sun Seo Andrew M. Weiner

We present a novel direct space-to-time pulse shaper, operating in the 1.5m optical communications band which enables generation of continuous optical pulse sequences at a rate of 100GHz. The apparatus includes several novel features, such as the use of a diffractive optical element for spatial patterning, fiber coupled input/output, and a telescopic configuration which collectively enable gene...

Journal: :Optics express 2009
Yuankun Lin Ahmad Harb Karen Lozano Di Xu K P Chen

This paper demonstrates an approach for laser holographic patterning of three-dimensional photonic lattice structures using a single diffractive optical element. The diffractive optical element is fabricated by recording gratings in a photosensitive polymer using a two-beam interference method and has four diffraction gratings oriented with four-fold symmetry around a central opening. Four firs...

2002
Yongqi Fu Ngoi Kok Ann Bryan

Optical properties (transmission and refractive index) and chemical structure (XPS) of diamond-like coating (DLC) film before and after focused ion beam milling (FIBM) process, were investigated in this paper. It is shown by our FIBM experiment that influence of FIBM on Optical properties and chemical structure of the DLC film is not apparent, especially in near-infra region. The film still ca...

2012
Atsushi Motogaito Kazumasa Hiramatsu

Two types of lenses can focus light: an optical lens using refraction phenomenon and a diffractive lens using diffraction phenomena. Table 1 shows the characteristics of each lens. The focal length of the diffractive lens is controlled by the structures of the lens, as mentioned in detail in Section 2.2. This suggests that the focal length of the diffractive lens is independent of refractive in...

2001
Lars R. Lindvold

The purpose of this article is to provide the reader with an up-to-date status on the commercial applications of diffractive optical elements. Rather than merely treating these as individual components, this article will also focus on the their applications from a systems point-of-view. Diffractive optics − an introduction Diffractive optics, as the name implies, are based on the principle of d...

2003
A. Meyer

A combination of laser-induced ultrasound generation and ultrasonic holography for spatial control of the generated ultrasonic pulse is presented. Ultrasound is produced by absorption of laser pulses at an absorbing layer in a water tank via the optoacoustic effect. In order to produce a defined ultrasonic frequency in the MHz range, the laser pulses are harmonically time-modulated using an aco...

Journal: :Applied optics 2000
S Cha P C Lin L Zhu P C Sun Y Fainman

A confocal microscope profilometer, which incorporates chromatic depth scanning with a diffractive optical element and a digital micromirror device for configurable transverse scanning, provides three-dimensional (3D) quantitative measurements without mechanical translation of either the sample or the microscope. We used a microscope with various objective lenses (e.g., 40x, 60x, and 100x) to a...

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