27.—The Zeros of Optical Coherence Functions and their Utility in the Study of Spectra

Author(s):  
G. M. Thomas

SynopsisThis paper shows that the coherence function associated with a band-limited optical spectrum is expressible as an infinite product involving its zeros. Only a finite number of zeros are physically significant and these can be determined from measurements of the visibility of interference fringes; but an ambiguity remains in the sign of the imaginary part of each zero. If the spectrum is to be recovered using the visibility measurements, an auxiliary experiment is needed to supply the necessary signs, but it need not be especially accurate. If the signs are not known there is only a limited number of different spectra that are compatible with the visibility measurements. Finally it is suggested that wavelength measurements made on an asymmetric spectral line with a Michelson interferometer may yield differing results when used with long and short delays.

2017 ◽  
Vol 9 (6) ◽  
pp. 67
Author(s):  
Tadeusz Wajda

The study addresses the issue of the so-called time dilation in the sense of the origin of its creation and the physical existence.Based on the work of Lorentz, who the lack of displacement of interference fringes in the Michelson interferometer explained wrongly with, shortening one arm of the interferometer, I propose the construction of the light pulse clock, in which to measure the rate of the passage of time is used constancy speed of light in vacuum.Light clock, the construction of which is described in the paper, stationary in relation to the ether, will measure constant time intervals. The same clock transported, will slow down the pace of his walk as a function of transportation speed v and that is a novelty, will slow depending on its orientation relative to the direction of motion. Light clock transported transversely with respect to the stationary clock will slow gamma times, transported lengthwise will slow gamma to the second power.Basing on the obtained dependences I maintain that time dilation defined in the theory of relativity (SR) as the slowing of the lapse of time, does not physically exist and identification the varying pace of walk clock with the pace of lapse of time I consider a fundamental error resulting from the postulates of this theory.


1979 ◽  
Vol 49 ◽  
pp. 67-82
Author(s):  
J.E. Baldwin ◽  
P.J. Warner

Much ingenuity has been devoted to the determination of mutual coherence functions at radio wavelengths. Measurements of the amplitude and phase of the interference fringes with uncertainties of only 1 percent are now attainable. Unfortunately the atmosphere intervenes between the measured quantities and the mutual coherence function itself and the phase uncertainties introduced by the ionospheric and tropospheric irregularities are often the factor limiting the quality of radioastronomical maps.


2012 ◽  
Vol 17 (5) ◽  
pp. 618-629
Author(s):  
Hamidreza Marasi ◽  
Aliasghar Jodayree Akbarfam

In this paper the differential equation y″ + (ρ 2 φ 2 (x) –q(x))y = 0 is considered on a finite interval I, say I = [0, 1], where q is a positive sufficiently smooth function and ρ 2 is a real parameter. Also, [0, 1] contains a finite number of zeros of φ 2 , the so called turning points, 0 < x 1 < x 2 < … < x m < 1. First we obtain the infinite product representation of the solution. The product representation, satisfies in the original equation. As a result the associated dual equation is derived and then we proceed with the solution of the inverse problem.


2004 ◽  
Vol 22 (3) ◽  
pp. 279-284 ◽  
Author(s):  
ANNE-SOPHIE MORLENS ◽  
PHILIPPE ZEITOUN ◽  
LAURENT VANBOSTAL ◽  
PASCAL MERCERE ◽  
GRÉGORY FAIVRE ◽  
...  

A XUV Michelson interferometer has been developed by LIXAM/CEA/LCFIO and has been tested as a Fourier-transform spectrometer for measurement of X-ray laser line shape. The observed strong deformation of the interference fringes limited the interest of such an interferometer for plasma probing. Because the fringe deformation was coming from a distortion of the beam splitter (5 × 5 mm2open aperture, about 150 nm thick), several parameters of the multilayer deposition used for the beam splitter fabrication have been recently optimized. The flatness has been improved from 80 nm rms obtained by using the ion beam sputtering technique, to 20 nm rms by using the magnetron sputtering technique. Over 3 × 3 mm2, the beam splitter has a flatness better than 4 nm rms.


2021 ◽  
Vol 29 (20) ◽  
pp. 32006
Author(s):  
Chen Yang ◽  
Zhi-Yuan Zhou ◽  
Liu-Long Wang ◽  
Yan Li ◽  
Shi-Kai Liu ◽  
...  

1999 ◽  
Vol 22 (3) ◽  
pp. 445-458
Author(s):  
Marcel Berland

We introduce the notions of Ritt order and type to functions defined by the series∑n=1∞fn(σ+iτ0)exp(−sλn),      s=σ+iτ,(σ,τ)∈R×R                                            (*)indexed byτ0onR, where(λn)1∞is aD-sequence and(fn)1∞is a sequence of entire functions of bounded index with at most a finite number of zeros. By definition, the series areBE-Dirichletian elements. The notions of order and type of functions, defined byB-Dirichletian elements, are considered in [3, 4]. In this paper, using a technique similar to that used by M. Blambert and M. Berland [6], we prove the same properties of Ritt order and type for these functions.


2021 ◽  
Author(s):  
Tingyu Yan ◽  
Jeffery A. Langille ◽  
William E. Ward ◽  
William A. Gault ◽  
Alan Scott ◽  
...  

Abstract. A new compact static birefringent Doppler wind imaging interferometer has been developed for the purpose of observing upper atmospheric winds using suitably isolated airglow emissions. The instrument, called the Birefringent Doppler Wind imaging Interferometer (BIDWIN), combines a field widened birefringent delay plate placed between two crossed Wollaston prisms with an imaging system, waveplates and polarizers to produce four fixed 90-degree phase stepped images of the interference fringes conjugate to the scene of interest. A four-point algorithm is used to extract line of sight Doppler wind measurements across the image of the scene. The arrangement provides a similar throughput to that of a field widened Michelson interferometer, albeit constructed without moving parts. Consequently, the instrument provides a compact, lightweight and robust alternative. In this paper, the instrument concept is presented and the design and optimization of a prototype version of the instrument is discussed. Characterization of the lab prototype is presented and the performance of the instrument is examined by applying the instrument to measure a low velocity two-dimensional Doppler wind field with a high precision (5 m/s) in the lab.


2019 ◽  
pp. 35-38
Author(s):  
I.A. Afanasіeva ◽  
S.N. Afanasiev ◽  
V.V. Bobkov ◽  
V.V. Gritsyna ◽  
D.R. Drozdov ◽  
...  

To obtain the qualitative and quantitative characteristics of the discharge plasma spectrum in the Python programming language, a multifunctional interactive GUI-application OSA (Optical Spectrum Analyzed) was created. The application allows you to download a digital image of the optical spectrum, automatically determine the wavelength of the selected spectral line and do elements interpretation.


1940 ◽  
Vol 36 (3) ◽  
pp. 283-287 ◽  
Author(s):  
J. C. P. Miller

This paper gives a criterion for determining whether real, non-zero solutions of a linear differential equation of the second order have an infinite or a finite number of zeros, or, in short, are oscillatory or non-oscillatory, as the independent variable tends to infinity.


Sign in / Sign up

Export Citation Format

Share Document