Wave-front phase estimation from Fourier intensity measurements

1989 ◽  
Vol 6 (7) ◽  
pp. 1020 ◽  
Author(s):  
J. N. Cederquist ◽  
J. R. Fienup ◽  
C. C. Wackerman ◽  
S. R. Robinson ◽  
D. Kryskowski
Keyword(s):  
Wave Front ◽  
Phase Estimation ◽  
Intensity Measurements

scholarly journals Versatile Super-Sensitive Metrology Using Induced Coherence

Quantum ◽  
2021 ◽  
Vol 5 ◽  
pp. 458
Author(s):  
Nathaniel R. Miller ◽  
Sven Ramelow ◽  
William N. Plick
Keyword(s):  
Bright Light ◽  
Phase Estimation ◽  
Practical Advantage ◽  
Intensity Measurements ◽  
Frequency Domains ◽  
Parametric Down Conversion ◽  
Potential Applications ◽  
Noise Limit ◽  
Down Conversion ◽  
Shot Noise Limit

We theoretically analyze the phase sensitivity of the Induced-Coherence (Mandel-Type) Interferometer, including the case where the sensitivity is "boosted" into the bright input regime with coherent-light seeding. We find scaling which reaches below the shot noise limit, even when seeding the spatial mode which does not interact with the sample – or when seeding the undetected mode. It is a hybrid of a linear and a non-linear (Yurke-Type) interferometer, and aside from the supersensitivity, is distinguished from other systems by "preferring" an imbalance in the gains of the two non-linearities (with the second gain being optimal at low values), and non-monotonic behavior of the sensitivity as a function of the gain of the second non-linearity. Furthermore, the setup allows use of subtracted intensity measurements, instead of direct (additive) or homodyne measurements – a significant practical advantage. Bright, super-sensitive phase estimation of an object with different light fields for interaction and detection is possible, with various potential applications, especially in cases where the sample may be sensitive to light, or is most interesting in frequency domains outside what is easily detected, or when desiring bright-light phase estimation with sensitive/delicate detectors. We use an analysis in terms of general squeezing and discover that super-sensitivity occurs only in this case – that is, the effect is not present with the spontaneous-parametric-down-conversion approximation, which many previous analyses and experiments have focused on.

Thickness and composition determinations from T.E.M. specimens using both x-ray and backscattered electron data

1984 ◽  
Vol 42 ◽  
pp. 576-577
Author(s):  
M.D. Ball ◽  
H. Lagace ◽  
M.C. Thornton
Keyword(s):  
Electron Microscope ◽  
Atomic Number ◽  
Transmission Electron Microscope ◽  
Convenient Method ◽  
Flow Chart ◽  
X Ray ◽  
Intensity Measurements ◽  
Transmission Electron ◽  
Electron Intensity ◽  
Backscattered Electron

The backscattered electron coefficient η for transmission electron microscope specimens depends on both the atomic number Z and the thickness t. Hence for specimens of known atomic number, the thickness can be determined from backscattered electron coefficient measurements. This work describes a simple and convenient method of estimating the thickness and the corrected composition of areas of uncertain atomic number by combining x-ray microanalysis and backscattered electron intensity measurements.The method is best described in terms of the flow chart shown In Figure 1. Having selected a feature of interest, x-ray microanalysis data is recorded and used to estimate the composition. At this stage thickness corrections for absorption and fluorescence are not performed.

Wave-front evaluation of the Ni-like Ag laser

2001 ◽  
Vol 11 (PR2) ◽  
pp. Pr2-155-Pr2-158 ◽  
Author(s):  
K. Murai ◽  
S. Sebban ◽  
H. J. Tang ◽  
Y. Yoshizumi ◽  
H. Daido ◽  
...  
Keyword(s):  
Wave Front

An Absolute Phase Estimation Method for Interferometry Imagery

2019 ◽  
Vol 1 (2) ◽  
pp. 14-19
Author(s):  
Sui Ping Lee ◽  
Yee Kit Chan ◽  
Tien Sze Lim
Keyword(s):  
Noise Suppression ◽  
Estimation Method ◽  
Phase Image ◽  
Phase Estimation ◽  
Phase Reconstruction ◽  
Estimation Algorithms ◽  
Absolute Phase ◽  
Filtering Rate ◽  
Interferometric Phase ◽  
Image Performance

Accurate interpretation of interferometric image requires an extremely challenging task based on actual phase reconstruction for incomplete noise observation. In spite of the establishment of comprehensive solutions, until now, a guaranteed means of solution method is yet to exist. The initially observed interferometric image is formed by 2π-periodic phase image that wrapped within (-π, π]. Such inverse problem is further corrupted by noise distortion and leads to the degradation of interferometric image. In order to overcome this, an effective algorithm that enables noise suppression and absolute phase reconstruction of interferometric phase image is proposed. The proposed method incorporates an improved order statistical filter that is able to adjust or vary on its filtering rate by adapting to phase noise level of relevant interferometric image. Performance of proposed method is evaluated and compared with other existing phase estimation algorithms. The comparison is based on a series of computer simulated and real interferometric data images. The experiment results illustrate the effectiveness and competency of the proposed method.

Wave-front inversion in induced light scattering

1978 ◽  
Vol 126 (12) ◽  
pp. 683-686
Author(s):  
Boris Ya. Zel'dovich ◽  
V.V. Ragul'skii
Keyword(s):  
Light Scattering ◽  
Wave Front
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