Nonlinear phase measurement using a coherent state in noisy environments

2021 ◽  
Author(s):  
Baohua Yang ◽  
Huajie Zou ◽  
Weijie Gu
Keyword(s):  
Coherent State ◽  
Phase Measurement ◽  
Noisy Environments ◽  
Nonlinear Phase

MINIMUM UNCERTAINTY RELATION OBEYED BY SWH PHASE OPERATOR IN TWO-MODE COHERENT STATE

1999 ◽  
Vol 13 (14) ◽  
pp. 463-469 ◽  
Author(s):  
FAN HONGYI ◽  
SUN ZHIHU
Keyword(s):  
Coherent State ◽  
Uncertainty Relation ◽  
Phase Measurement ◽  
Single Mode ◽  
Square Root ◽  
Phase Operator ◽  
Expectation Values ◽  
Measurement Scheme ◽  
Minimum Uncertainty ◽  
Root Operation

We study the minimum uncertainty relation obeyed by the phase operator [Formula: see text] in two-mode coherent state. The operator is suitable for Shapiro–Wagner heterodyne phase measurement scheme. It is due to the |ξ> representation (see Eq. (4)) that the difficulty brought by nonlinear square root operation in [Formula: see text] can be avoided in calculating miscellaneous expectation values. Just as the single-mode coherent state | z1> makes uncertainty relation, satisfied by S–G phase operator, minimum for large |z1|2, we show that |z1,z2> makes uncertainty relation obeyed by [Formula: see text] minimum when |z1|=|z2| is large enough. Some figures are plotted to support our conclusion.

scholarly journals Coherent state phase estimation based on digital nonlinear phase-locked loop

2019 ◽  
Vol 68 (2) ◽  
pp. 024204
Author(s):  
Han Xu ◽  
Shu-Xin Chen ◽  
Hao Wu ◽  
Kun Chen ◽  
Lei Hong
Keyword(s):  
Coherent State ◽  
Phase Locked Loop ◽  
Phase Estimation ◽  
Nonlinear Phase

Performance and applications of the holography electron microscope

1993 ◽  
Vol 51 ◽  
pp. 1078-1079
Author(s):  
Akira Tonomura
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Phase Measurement ◽  
Electron Holography ◽  
Imaging Method ◽  
High Contrast ◽  
Magnetic Lens ◽  
High Brightness ◽  
Holographic Imaging ◽  
Dynamic Observation

Electron holography is a two-step imaging method. However, the ultimate performance of holographic imaging is mainly determined by the brightness of the electron beam used in the hologram-formation process. In our 350kV holography electron microscope (see Fig. 1), the decrease in the inherently high brightness of field-emitted electrons is minimized by superposing a magnetic lens in the gun, for a resulting value of 2 × 109 A/cm2 sr. This high brightness has lead to the following distinguished features. The minimum spacing (d) of carrier fringes is d = 0.09 Å, thus allowing a reconstructed image with a resolution, at least in principle, as high as 3d=0.3 Å. The precision in phase measurement can be as high as 2π/100, since the position of fringes can be known precisely from a high-contrast hologram formed under highly collimated illumination. Dynamic observation becomes possible because the current density is high.

Improvement of Quasi-Optimum Quantum Receiver for 3-PSK Coherent-State Signals

2009 ◽  
Vol 129 (12) ◽  
pp. 2159-2160
Author(s):  
Asami Imaeda ◽  
Masahiro Yoshikawa ◽  
Tsuyoshi Sasaki
Keyword(s):  
Coherent State

Nonlinear Phase Radio-Range Station for Measuring Distance to Radio Emission Sources

2007 ◽  
Vol 66 (1) ◽  
pp. 63-67
Author(s):  
N. I. Kozachek ◽  
Vladimir B. Avdeev ◽  
D. V. Senkevich ◽  
S. N. Panychev
Keyword(s):  
Radio Emission ◽  
Emission Sources ◽  
Nonlinear Phase ◽  
Radio Range

SMART IDENTIFICATION OF POWER QUALITY EVENTS USING NEW STOCKWELL TRANSFORM AND MACHINE LEARNING ALGORITHM

2019 ◽  
Vol XVI (4) ◽  
pp. 95-113
Author(s):  
Muhammad Tariq ◽  
Tahir Mehmood
Keyword(s):  
Machine Learning ◽  
Power Quality ◽  
Learning Algorithm ◽  
Machine Learning Algorithm ◽  
Noisy Environments ◽  
Satisfactory Performance ◽  
Feature Values ◽  
Learning Machine ◽  
Stockwell Transform ◽  
Electrical Utilities

Accurate detection, classification and mitigation of power quality (PQ) distortive events are of utmost importance for electrical utilities and corporations. An integrated mechanism is proposed in this paper for the identification of PQ distortive events. The proposed features are extracted from the waveforms of the distortive events using modified form of Stockwell’s transform. The categories of the distortive events were determined based on these feature values by applying extreme learning machine as an intelligent classifier. The proposed methodology was tested under the influence of both the noisy and noiseless environments on a database of seven thousand five hundred simulated waveforms of distortive events which classify fifteen types of PQ events such as impulses, interruptions, sags and swells, notches, oscillatory transients, harmonics, and flickering as single stage events with their possible integrations. The results of the analysis indicated satisfactory performance of the proposed method in terms of accuracy in classifying the events in addition to its reduced sensitivity under various noisy environments.

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