Defocus measurement using a liquid crystal point diffraction interferometer

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Published by National Aeronautics and Space Administration, National Technical Information Service, distributor in [Washington, DC], [Springfield, Va .

Written in English

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StatementCarolyn R. Mercer and Katherine Creath.
SeriesNASA technical memorandum -- 106687.
ContributionsCreath, Katherine., United States. National Aeronautics and Space Administration.
The Physical Object
Pagination1 v.
ID Numbers
Open LibraryOL17001220M

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A new optical instrument, the liquid crystal point diffraction interferometer (LCPDI), is used to measure the temperature distribution across a heated chamber filled with silicone oil.

Defocus Measurement Using A Liquid Crystal Point Diffraction Interferometer Carolyn R. Mercer NASA Lewis Research Center, Cleveland, OH ph: fax: Katherine Creath Optical Sciences Center University of Arizona, Tucson, AZ. Get this from a library. Defocus measurement using a liquid crystal point diffraction interferometer.

[Carolyn R Mercer; Katherine Creath; United States. National Aeronautics and Space Administration.]. A point diffraction interferometer (PDI) is a type of common-path an amplitude-splitting interferometer, such as a Michelson interferometer, which separates out an unaberrated beam and interferes this with the test beam, a common-path interferometer generates its own reference PDI systems, the test and reference beams travel the same or almost the same path.

Liquid-crystal point-diffraction interferometer for wave-front measurements Carolyn R. Mercer and Katherine Creath A new instrument, the liquid-crystal point-diffraction interferometer:LCPDI), is developed for the measurement of phase objects. This instrument maintains the. A new instrument, the liquid crystal point diffraction interferometer (LCPDI) has recently been described.' The LCPDI is based on the point diffraction interferometer.

2,3 It is made from a thin liquid crystal layer sandwiched between glass plates, with an embedded microsphere serving as. Liquid-crystal point-diffraction interferometer for wave-front measurements Carolyn R.

Mercer and Katherine Creath Anew instrument, the liquid-crystal point-diffraction interferometer 1LCPDI2, is developed for the. Two-shot point-diffraction interferometer with an unknown phase shift Fuzhong Bai et al Journal of Optics 12 IOPscience.

Double-pass point diffraction interferometer Hagyong Kihm and Yun-Woo Lee Measurement Science and Technology 21 IOPscience. A fiber-diffraction interferometer using a coherent fiber optic taper.

The point diffraction interferometer (PDI) has long been used for the measurement of optical wavefronts for lens testing and fluid flow diagnostics. It was invented by Linnik, 1. Point diffraction interferometer with a liquid Mercer and K. Creath, “Liquid-crystal point-diffraction interferometer,” Opt.

Lett. 19(12), – etc. The Point Diffraction Interferometer (PDI) [3] is an in-line common path interferometer, thus more robust and compact, and that tolerates the use of.

We describe a novel interferometer design suitable for highly accurate measurement of wave-front aberrations over a wide range of wavelengths, from visible to x ray. The new design, based on the point diffraction interferometer, preserves the advantages of the conventional point diffraction interferometer but offers higher efficiency and improved accuracy through phase shifting.

Optical wavefront measurement using a novel phase-shifting point-diffraction interferometer | SPIE Newsroom: SPIE 5/16/12 PM ultraviolet phase-shifting point-diffraction interferometer: a wave-front metrology tool K.

Creath, Liquid-crystal point-diffraction interferometer for wave-front measurements, Appl. Opt. 35, pp.In this work a novel point diffraction interferometer based on a variable liquid crystal wave plate (LCWP) has been implemented.

The LCWP consists of a 3x3 cm2 monopixel cell with parallel alignment. The monopixel cell was manufactured such that the electrode covers the entire surface except in a centered circular area of 50 μm of diameter.

In the present paper, a point diffraction interferometer using an optical saturable absorber is proposed. In this system, the small dot is generated automatically on the film and the focal point is self-aligned.

We now consider a standard PDI consisting of a Fourier transform lens and a. CONICET Digital, el repositorio institucional del CONICET, un servicio gratuito para acceder a Defocus measurement using a liquid crystal point diffraction interferometer book producción científico-tecnológica de investigadores, becarios y demás personal del CONICET.

To overcome the accuracy limitation in traditional commercial interferometers, the phase shifting point diffraction interferometer (PPDI) has been developed for spherical surface figure measurement on a sub-nanometer scale, which applies a point aperture to generate a spherical wavefront as the ideal reference wavefront.

In the point Cited by: 1. We demonstrate a phase-shifting, point diffraction interferometer that achieves high accuracy and is capable of measuring a single pulse of light. The measurement system utilizes a polarizing point diffraction plate to generate a synthetic reference beam that is.

Defocus measurement using a liquid crystal point diffraction interferometer: OSA Optical Fabrication and Testing Workshop Digest: interferometry: Book Section: C. Mercer, and K. Creath: Defocus measurement using a liquid crystal point diffraction interferometer, NASA technical memorandum NASA technical memorandum 1.

Introduction. Interferometric phase microscopy (IPM) is a powerful label-free tool for studying biological specimens, surface measurements, and micro structures.In order to obtain phase distribution of the specimen, many IPM optical geometries have been proposed over the years, including common-path geometries and separated-path by: 8.

The plate of the PDI has a micro-hole and transmittance of less than 10%. The experimental setup consists in a He-Ne laser illuminating a spatial filter, a collimated beam is produced by an achromatic lens, and close to the focal point of a second lens (focusing lens), the plate of the Point Diffraction Interferometer is : E.

Rueda-Soriano, F. Granados-Agustín, A. Cornejo-Rodríguez, Elizabeth Percino-Zacarías, P. Cebri. A phase-shifting point diffraction interferometer (PS/PDI) with point sources of two single mode optical fibers has been developed, which will be appropriate for the surface figure measurement of large aperture optics on a sub-nanometer by: 8.

Interferometric method for phase calibration in liquid crystal spatial light modulators using a self-generated diffraction-grating José Luis Martínez Fuentes,1,2,3 Enrique J.

Fernández,2 Pedro M. Prieto,2 and Pablo Artal2 1Instituto de Investigación en Óptica y Nanofísica, Laboratorio de Óptica, Universidad de Murcia, Edifi Campus de Espinardo, Murcia, SpainFile Size: 3MB.

Author(s): Estey, Brian Vincent | Advisor(s): Mueller, Holger | Abstract: We experimentally and theoretically study Bragg diffraction as a tool for large-momentum transfer beam splitters in atom interferometry. A theoretical framework is developed to quantify the diffraction phase systematic caused by Bragg diffraction and experiments are performed to confirm these predictions using a Ramsey Cited by: 1.

Extreme-ultraviolet phase-shifting point-diffraction interferometer: a wave-front metrology tool with subangstrom reference-wave accuracy. Naulleau PP(1), Goldberg KA, Lee SH, Chang C, Attwood D, Bokor J.

Author information: (1)Center for X-Ray Optics, Lawrence Berkeley National Laboratory, Berkeley, CaliforniaUSA. [email protected] by: Procedure for determining defocus. Measure the radius of the first CTF minimum on the optical diffraction pattern of a drift-free area of carbon film on your negative.

Note that if the defocus is less than nm, it will be very difficult to see the minimum. Using a PC in the lab, run the CTF program (type 'ctf').

Revealing features of different optical shaping technologies by a point diffraction interferometer Nikolay Voznesenskiya, Mariia Voznesenskaiaa, Diwaker Jhaa, Heidi Ottevaereb, MałgorzataKujawińskac, Maciej Trusiakc, Kamil Liżewskic aDifrotec OÜ, Teaduspa Tartu, Estonia; bVrije Universiteit Brussel, Department of Applied Physics and Photonics, Brussels.

Interferometry is a family of techniques in which waves, usually electromagnetic waves, are superimposed, causing the phenomenon of interference, which is used to extract information. Interferometry is an important investigative technique in the fields of astronomy, fiber optics, engineering metrology, optical metrology, oceanography, seismology, spectroscopy (and its applications to.

We propose a new point-diffraction interferometer (PDI) based on a pinhole filter made by a z-cut lithium niobate (LN) crystal. A thin aluminium layer with a circular opening is fabricated on the surface of the crystal by conventional photolithography and subsequent aluminium deposition and : M.

Paturzo, S. Grilli, P. Ferraro. Abstract Not Available Bibtex entry for this abstract Preferred format for this abstract (see Preferences): Find Similar Abstracts. A lensless reflective point diffraction interferometer (LRPDI) is proposed for dynamic wavefront measurement. The point diffraction interferometer is integrated on a small substrate with properly designed thin film, which is used for generating the Cited by: 4.

Journal of the European Optical Society - Rapid publications, Vol 10 () Simple quasi-common path point diffraction interferometer with adjustable fringe contrast and carrier frequency F. Bai, Y. Miao, H. Guo, X. Gao, X. Wang. Measurement techniques based on optical interferometry are widely used for the determination of thermal expansion coefficients smaller than about 1 ppm/oC.

The principle methods are Fabry-Perot, Fizeau (including Abbe-Pulfrich and Priest), holographic, Michelson, Moiré, and speckle interferometers, and diffraction techniques.

J. Zhao, Y. Zhang, H. Jiang, J. Di, Dynamic measurement for the solution concentration variation using digital holographic interferometry and discussion for the measuring accuracy, in International Conference on Optics in Precision Engineering and Nanotechnology Proc.

of SPIE, vol., pp. D1–D18 Google ScholarAuthor: Carlos Guerrero-Mendez, Tonatiuh Saucedo-Anaya, M. Araiza-Esquivel, Enrique De la Rosa, Carlos Olver. Abstract. This paper reviews the convergent-beam electron diffraction (CBED) technique.

Point- and space-group determination methods of ordinary crystals are described, along with an example of the determination method for Sr 3 Ru 2 O symmetry determination of one-dimensionally incommensurate crystals and quasicrystals is by:   Point Diffraction Interferometer for ATMs - posted in ATM, Optics and DIY Forum: Point-diffraction interferometer, or just PDI is probably one interferometer every ATM can make, and probably should make because its so ridiculously simple and inexpensive.

There are no special optics required, and the results can be quantified with free fringe analysis software, such as FringeXP and OpenFringe. The powders were suspended in liquid in a stirred measuring cell (Malvern, type PS14).

The pathlength of the light passing through this cell is millimeters. The process of measurement was controlled by a microcomputer. An experiment was preceded by a measurement of the background which is sub- tracted from the time average by: interferometer four times, then emerges along its original path.

1 2 The confocal Fabry-Perot interferometer has a higher throughput than the plane Fabry-Perot interferometer and produces a uniform output field.

It is, therefore the preferred form for operation in a scanning mode by using piezoelectric spacers to vary the separation of the File Size: 2MB. Yokozeki and K. Ohnishi, "Spherical aberration measurement with shearing interferometer using Fourier imaging and moiré method," Applied opt ().

Ma, X. Wang, and F. Wang, "Aberration measurement of projection optics in lithographic tools based on two-beam interference theory," Applied opt ( Using this system, the following experimental examples can be conducted: Fraunhofer Diffraction (Far-field) 1. Fraunhofer diffraction through a single-slit.

Fraunhofer diffraction through a multi-slit plate. Fraunhofer diffraction through a single circular aperture. Fraunhofer diffraction through a transmission grating Fresnel. Michelson™s interferometer has become a widely used instrument for measuring the wavelength of light, for using the wavelength of a known light source to measure extremely small distances, and for investigating optical media.

Figure 1 shows a diagram of a Michelson interferometer. The beam of light from the laser strikes the beam-splitter,File Size: KB.

Experiment 4 – The Michelson Interferometer 2 Figure 1: Schematic illustration of a Michelson interferometer. path to make each path have the same optical path length when M 1 and M 2 are the same distance from the beam splitter. After returning from M 1, 50% of the light is reflected toward the frosted glass screen.Procedure of aberration determination based on diffractogram.

In the aberration measurement method based on diffractogram, the prerequisite is an accurate determination of defocus and twofold astigmatism from each diffractogram. A constant defocus must presents over the field of view on the thin amorphous area used to record diffractograms.aberrations.

Wavefront measurement using an interferometer only provides data at a single field point. This causes field curvature to look like focus, and distortion to look like tilt. Therefore, a number of field points must be measured to determine the Seidel aberrations.

Rewriting the Zernike expansion of Eq. (57), first- and third-order field.

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