Direct phase measurements in phase-shift masks

1992 ◽  
Author(s):  
Amalkumar P. Ghosh ◽  
Derek B. Dove
Keyword(s):  
Phase Shift ◽  
Phase Measurements

Influence of condenser microphones on phase measurements in photoacoustics at low pressure

1986 ◽  
Vol 64 (9) ◽  
pp. 1111-1115
Author(s):  
G. Louis ◽  
F. Lepoutre ◽  
J. P. Monchalin
Keyword(s):  
Phase Shift ◽  
Photoacoustic Signal ◽  
Low Pressure ◽  
Response Magnitude ◽  
Phase Measurements ◽  
Condenser Microphone ◽  
Slip Effects ◽  
Shift Response ◽  
Lumped Parameters

Condenser microphones used as photoacoustic signal detectors exhibit a phase-shift response that depends on both the nature and the pressure of the ambient filling gas. In this paper, we develop a lumped-parameters model of the microphone damping in which the approximations are thoroughly discussed. This model, after taking into account gas-slip effects on the surfaces of the condenser cartridge plates, is shown to accurately describe the response (magnitude and phase) of a commercial condenser microphone (Brüel and Kjaer 4144) for frequencies below 2.2 kHz and ambient pressures between 1.5 × 103 and 6 × 104 Pa.

MONOFREQUENCY BOREHOLE TRAVELTIME SURVEY

Geophysics ◽  
1977 ◽  
Vol 42 (6) ◽  
pp. 1137-1145 ◽  
Author(s):  
R. W. Ward ◽  
M. R. Hewitt
Keyword(s):  
Phase Shift ◽  
Measurement System ◽  
Phase Measurement ◽  
Compressional Wave ◽  
Computer Processing ◽  
Surface Source ◽  
Efficient Operation ◽  
Phase Measurements ◽  
Novel Technique ◽  
The Difference

A novel technique was successfully tested to measure compressional‐wave traveltime from a vibrator surface source, using monofrequency pilot signals, to a borehole seismometer. The difference between traveltime measurements by a direct‐phase‐measurement system and those obtained by computer processing of the digitally recorded monofrequency signals was a fraction (0.2 − 0.3) of a millisecond. Absolute monofrequency traveltime measurements obtained by adding integral numbers of signal cycles to phase measurements were not consistent for two different frequencies at the same depth. The suspected cause of this inconsistency is a frequency‐dependent phase shift, due to vibrator‐earth coupling, between the baseplate accelerometer and the borehole seismometer. However, adjustment of the two monofrequency (35 Hz and 55 Hz) traveltime surveys to match the check‐shot traveltime to the 600 ft depth produced excellent agreement between the two monofrequency traveltime surveys and the check‐shot traveltimes. After adjustment, the rms traveltime difference between the 35 Hz survey and the check‐shot survey was 2.5 msec and between the 55 Hz survey and the check‐shot survey was 1.3 msec. Several possible advantages of this technique include the use of a source which is more acceptable in some environments, ability to obtain a digital traveltime reading in the field, and more efficient operation than conventional surveys.

Phame: phase measurements on 45nm node phase shift features

2008 ◽  
Author(s):  
Ute Buttgereit ◽  
Robert Birkner ◽  
Dirk Seidel ◽  
Sascha Perlitz ◽  
Vicky Philipsen ◽  
...  
Keyword(s):  
Phase Shift ◽  
Phase Measurements

Interferometer for phase measurements in phase-shift masks

1993 ◽  
Author(s):  
Derek B. Dove ◽  
T. C. Chieu ◽  
Amalkumar P. Ghosh
Keyword(s):  
Phase Shift ◽  
Phase Measurements

scholarly journals Quantitative phase measurements of human cell nuclei using X-ray ptychography

2021 ◽  
Vol 28 (4) ◽  
Author(s):  
Jorg Schwenke ◽  
Mohammed Yusuf ◽  
Laura A. Shemilt ◽  
Ulrich Wagner ◽  
Atiqa Sajid ◽  
...  
Keyword(s):  
Phase Shift ◽  
Human Cell ◽  
Cell Nuclei ◽  
Diffractive Imaging ◽  
Phase Measurements ◽  
X Ray ◽  
Large Structures ◽  
Quantitative Measurements ◽  
The Masses

The human cell nucleus serves as an important organelle holding the genetic blueprint for life. In this work, X-ray ptychography was applied to assess the masses of human cell nuclei using its unique phase shift information. Measurements were carried out at the I13-1 beamline at the Diamond Light Source that has extremely large transverse coherence properties. The ptychographic diffractive imaging approach allowed imaging of large structures that gave quantitative measurements of the phase shift in 2D projections. In this paper a modified ptychography algorithm that improves the quality of the reconstruction for weak scattering samples is presented. The application of this approach to calculate the mass of several human nuclei is also demonstrated.

Object Wave Determination by Single-Sideband Methods

1973 ◽  
Vol 31 ◽  
pp. 266-267
Author(s):  
Kenneth H. Downing ◽  
Benjamin M. Siegel
Keyword(s):  
Phase Shift ◽  
Carbon Films ◽  
Object Wave ◽  
Electron Wave ◽  
Phase Object ◽  
Heavy Atoms ◽  
Single Sideband ◽  
Thin Carbon ◽  
Additional Phase Shift ◽  
Additional Phase

Under the “weak phase object” approximation, the component of the electron wave scattered by an object is phase shifted by π/2 with respect to the unscattered component. This phase shift has been confirmed for thin carbon films by many experiments dealing with image contrast and the contrast transfer theory. There is also an additional phase shift which is a function of the atomic number of the scattering atom. This shift is negligible for light atoms such as carbon, but becomes significant for heavy atoms as used for stains for biological specimens. The light elements are imaged as phase objects, while those atoms scattering with a larger phase shift may be imaged as amplitude objects. There is a great deal of interest in determining the complete object wave, i.e., both the phase and amplitude components of the electron wave leaving the object.

A Many-Beam Technique for Enhanced Resolution of Partial Dislocations

1972 ◽  
Vol 30 ◽  
pp. 646-647
Author(s):  
J. M. Oblak ◽  
B. H. Kear
Keyword(s):  
Phase Shift ◽  
Field Method ◽  
Dark Field ◽  
Bright Field ◽  
Field Technique ◽  
Weak Beam ◽  
Partial Dislocations ◽  
Enhanced Resolution ◽  
Nickel Base ◽  
Beam Technique

The “weak-beam” and systematic many-beam techniques are the currently available methods for resolution of closely spaced dislocations or other inhomogeneities imaged through strain contrast. The former is a dark field technique and image intensities are usually very weak. The latter is a bright field technique, but generally use of a high voltage instrument is required. In what follows a bright field method for obtaining enhanced resolution of partial dislocations at 100 KV accelerating potential will be described.A brief discussion of an application will first be given. A study of intermediate temperature creep processes in commercial nickel-base alloys strengthened by the Ll2 Ni3 Al γ precipitate has suggested that partial dislocations such as those labelled 1 and 2 in Fig. 1(a) are in reality composed of two closely spaced a/6 <112> Shockley partials. Stacking fault contrast, when present, tends to obscure resolution of the partials; thus, conditions for resolution must be chosen such that the phase shift at the fault is 0 or a multiple of 2π.

Observation of surface morphology by reflection electron holography

1989 ◽  
Vol 47 ◽  
pp. 536-537
Author(s):  
N. Osakabe ◽  
J. Endo ◽  
T. Matsuda ◽  
A. Tonomura
Keyword(s):  
Phase Shift ◽  
Surface Morphology ◽  
High Sensitivity ◽  
High Energy ◽  
Path Difference ◽  
Transmission Mode ◽  
Electron Holography ◽  
Dynamical Process ◽  
High Vertical Resolution ◽  
Amplification Technique

Progress in microscopy such as STM and TEM-TED has revealed surface structures in atomic dimension. REM has been used for the observation of surface dynamical process and surface morphology. Recently developed reflection electron holography, which employes REM optics to measure the phase shift of reflected electron, has been proved to be effective for the observation of surface morphology in high vertical resolution ≃ 0.01 Å.The key to the high sensitivity of the method is best shown by comparing the phase shift generation by surface topography with that in transmission mode. Difference in refractive index between vacuum and material Vo/2E≃10-4 owes the phase shift in transmission mode as shownn Fig. 1( a). While geometrical path difference is created in reflection mode( Fig. 1(b) ), which is measured interferometrically using high energy electron beam of wavelength ≃0.01 Å. Together with the phase amplification technique , the vertivcal resolution is expected to be ≤0.01 Å in an ideal case.

Inelastic mean free path and phase-shift determinations in NiO, using EXELFS

1993 ◽  
Vol 3 (7) ◽  
pp. 1649-1659
Author(s):  
Mohammad A. Tafreshi ◽  
Stefan Csillag ◽  
Zou Wei Yuan ◽  
Christian Bohm ◽  
Elisabeth Lefèvre ◽  
...  
Keyword(s):  
Phase Shift ◽  
Free Path ◽  
Mean Free Path ◽  
Inelastic Mean Free Path
Sign in / Sign up

Export Citation Format

Share Document