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1. Wave Nature of Light
1. Wave Nature of Light

... 1.1. Such an optical cavity is called a spherical mirror resonator, and is most commonly used in gas lasers. Sometimes, one of the reflectors is a plane mirror. The two spherical mirrors and the space between them form an optical resonator because only certain light waves with certain frequencies ca ...
Compressive Passive Millimeter Wave Imaging with Extended Depth of Field
Compressive Passive Millimeter Wave Imaging with Extended Depth of Field

... However, when used for short range imaging (as opposed to infinite conjugate imaging in astronomy) most mmW systems have a narrow depth-of-field (DoF), the distance over which an object is considered in focus. If individuals are moving toward an imager through a corridor, the weapons would be visibl ...
Pulsed Quasi-monochromatic x-ray source for radiography
Pulsed Quasi-monochromatic x-ray source for radiography

... gold target to generate gold x-rays. Other laser beam interacts with the target under investigation for the dynamic studies. We have introduced various objects to be radiographed and also Al foil for the x-ray Fig. 2: Spectrum of copper line emission in the spectral range imaging and absorption spec ...
Soft x-ray laser holography with wavelength resolution *
Soft x-ray laser holography with wavelength resolution *

... temporal and spatial coherence of the illuminating source, the resolution of the medium in which the hologram is recorded, and the digitization process used are also factors that influence the ultimate resolution. The experimental setup described in this paper was optimized to limit the degrading ef ...
Temperature Tuning Characteristics of Periodically Poled Lithium
Temperature Tuning Characteristics of Periodically Poled Lithium

... The phase matching temperature for this PPLN sample (with a periodicity of 5 µm) was calculated theoretically using the temperature dependent Sellemier equations4 and was found to be 113.14°C, which is in close agreement with the experimentally obtained value of 113°C. However, the broadband nature ...
Fundamentals of Optical Interferometry for Thermal Expansion
Fundamentals of Optical Interferometry for Thermal Expansion

... electronics, high speed photodetectors, CCD cameras and computerized data acquisition systems have considerably improved the versatility, range and resolution of interferometers, allowing a wide variety of applications (Table I). A major advantage of laser interferometry for length measurements is t ...
485-146 - Wseas.us
485-146 - Wseas.us

... transfer function is changed from stop-band to pass-band mode (Fig.1). Similar results can be obtained in the case of average refractive index discontinuity. For instance, If the average refractive index n0 of the homogeneous grating transforms into n0 + n/2 for the first half of the grating and n ...
Phase Change upon Reflection—CE Mungan, Spring 2008
Phase Change upon Reflection—CE Mungan, Spring 2008

... T ! It / Ii = t 2 n2 / n1 for normal incidence. Note that T and R are symmetric in n1 and n2. That is, the transmittance and reflectance are the same regardless of whether the beam is incident from the high or low index side of the interface. This conclusion can be neatly related to the Stokes relat ...
TEM - UiO
TEM - UiO

Hyperbolic Secant Squared Pulse Shape
Hyperbolic Secant Squared Pulse Shape

... effects on a pulse, one in space and the other in time. Dispersion disperses a pulse in space (angle): “Angular dispersion” ...
Chapter 4
Chapter 4

... refracted beam is partly along D' and partly along D". These polarization waves are solutions to the Fresnel equation for different indices of refraction. So one wave with polarization D' undergoes refraction corresponding to n', while the second polarization component D" is refracted by an index n" ...
Overview
Overview



... conductivity). The highly predictive character of the expressions derived by Kogelnik made his work one of the most cited by holographic researchers. Nonetheless Kogelnik’s theory assumed some approximations that make it inaccurate for some cases, such as dielectric gratings that are not sinusoidal ...
PDF
PDF

... collimated beam. The grating strength was modified along the antenna in order to create a constant intensity across the array length. Phase shifting was achieved using the thermo-optic effect in silicon. The use of an S-shaped waveguide allowed both a longer phase-shifter length in a small space and ...
No Slide Title
No Slide Title

... compounds fluoresce when bombarded with UV light. If the compound of interest fluoresces this is a very sensitive detector. The analyte is excited by light commonly at 253.7 nm from a low pressure mercury lamp. The light is absorbed and the molecule is excited and it gives off light of a different w ...
as PDF
as PDF

... Basically, a spectrometer is an optical system consisting of two lenses/mirrors that produces an image of the input slit on the detector. In between the lenses/mirrors is placed a diffraction grating which disperses different wavelengths in different angles. This causes different wavelengths of ligh ...
Interference
Interference

... If two light waves are present at the same place at the same time, their electric and magnetic fields add according to the superposition principle. If the two waves are in phase, they add constructively to produce a new wave with greater amplitude. If the two waves are 180° out of phase and have th ...
PDF Link
PDF Link

... loss of spatial coherence as the field propagates though a scattering medium of refractive index variance, σ n . In the absence of scattering, σ n  0, the coherence area becomes that of the incident plane wave, i.e., infinitely large. This result was obtained under the small angle approximation, so ...
Experiment 3 1 The Michelson Interferometer and the He
Experiment 3 1 The Michelson Interferometer and the He

... The  basic  idea  of  a  laser  is  illustrated  in  Fig.  3  where  the  energy  levels  of  an  atom  are   pictured.  In  the  normal  state,  almost  all  of  the  atoms  would  be  in  their  ground  state,  E1.  If,   on ...
الشريحة 1
الشريحة 1

... the lower plot, note the dramatic deviation from Beer’s law that results. ...
The Atomic, Molecular and Optical Science
The Atomic, Molecular and Optical Science

... and deflects it at a very shallow angle towards the interaction region. The second mirror is positioned downstream of the first and deflects the remaining portion of the beam along a slightly larger angle towards the interaction region. The silicon mirrors operate at angles less than 13.5 mrad and f ...
The Title Goes Here
The Title Goes Here

A Michelson Interferometer-Based Method For Measuring The Angle
A Michelson Interferometer-Based Method For Measuring The Angle

Imaging properties of a metamaterial superlens
Imaging properties of a metamaterial superlens

... Metamaterials have opened an exciting gateway to create unprecedented physical properties and functionality unattainable from naturally existing materials. The ‘‘atoms’’ and ‘‘molecules’’ in metamaterials can be tailored in shape and size; the lattice constant and interatomic interaction can be arti ...
Unit C POS Checklist
Unit C POS Checklist

...  compare and contrast the constituents of the electromagnetic spectrum on the basis of frequency and wavelength.  explain the propagation of EMR in terms of perpendicular electric and magnetic fields that are varying with time and travelling away from their source at the speed of light.  explain, ...
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Phase-contrast X-ray imaging



Phase-contrast X-ray imaging (PCI) or phase-sensitive X-ray imaging is a general term for different technical methods that use information concerning changes in the phase of an X-ray beam that passes through an object in order to create its images. Standard X-ray imaging techniques like radiography or computed tomography (CT) rely on a decrease of the X-ray beam's intensity (attenuation) when traversing the sample, which can be measured directly with the assistance of an X-ray detector. In PCI however, the beam's phase shift caused by the sample is not measured directly, but is transformed into variations in intensity, which then can be recorded by the detector.In addition to producing projection images, PCI, like conventional transmission, can be combined with tomographic techniques to obtain the 3D distribution of the real part of the refractive index of the sample. When applied to samples that consist of atoms with low atomic number Z, PCI is more sensitive to density variations in the sample than conventional transmission-based X-ray imaging. This leads to images with improved soft tissue contrast.In the last several years, a variety of phase-contrast X-ray imaging techniques have been developed, all of which are based on the observation of interference patterns between diffracted and undiffracted waves. The most common techniques are crystal interferometry, propagation-based imaging, analyzer-based imaging, edge-illumination and grating-based imaging (see below).
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