Understanding the concept of resolving power in the Fabry–Perot interferometer using a digital simulation

2006 ◽  
Vol 27 (5) ◽  
pp. 1111-1119 ◽  
Author(s):  
I Juvells ◽  
A Carnicer ◽  
J Ferré-Borrull ◽  
E Martín-Badosa ◽  
M Montes-Usategui
Keyword(s):  
Digital Simulation ◽  
Resolving Power ◽  
Fabry Perot

Characteristics of the defocused spherical Fabry-Pérot interferometer as a quasi-linear dispersion instrument for high resolution spectroscopy of pulsed laser sources

1968 ◽  
Vol 263 (1140) ◽  
pp. 209-223 ◽  
Keyword(s):  
Laser Beam ◽  
Optical Design ◽  
Pulsed Laser ◽  
Resolving Power ◽  
High Resolution Spectroscopy ◽  
Radius Of Curvature ◽  
Spherical Mirror ◽  
Linear Dispersion ◽  
Fabry Perot ◽  
Very High

Defocused spherical mirror Fabry—Pérot etalons, in which the mirror separation is slightly less than the common radius of curvature, produce a multiple-beam fringe pattern of concentric rings, with quasi-linear spectral dispersion over an appreciable annular region corresponding to two free spectral ranges. The characteristics of these interferograms are discussed in relation to their many advantages for pulsed laser spectroscopy. These advantages include: (i) accuracy of frequency difference measurement; (ii) high illumination of the detector with moderate energy density in the laser beam; (iii) ease of alinement and permanent adjustment of the mirrors leading to the attainment in practice of a very high instrumental finesse (N R values of up to 90 have been achieved); (iv) measurement of degree of spatial coherence of laser beam; (v) ease of matching the interferogram to the spatial resolution of the detector. A simple optical path relation determines the positions of the fringes and the location of the quasilinear dispersion region. The interfering wavefronts, formed by multiple reflexion, have been numerically computed and summed to provide information on the finesse, fringe profiles, contrast and optimum conditions of use of this new, very high resolving power (107 to 108) quasi-linear spectrographic disperser. Constructional details are described and optical design criteria are discussed, together with the various experimental arrangements for employing the instrument. Comparison is made with the equivalent confocal and plane Fabry—Pérot etalons and methods of simultaneously measuring

The Use of Fabry-Perot Filters for Spectral Scanning

1969 ◽  
Vol 1 (6) ◽  
pp. 293-294
Author(s):  
M. D. Waterworth
Keyword(s):  
Stellar Atmospheres ◽  
Spectral Lines ◽  
Resolving Power ◽  
Doppler Broadening ◽  
Collisional Broadening ◽  
Fabry Perot

In designing a stellar spectrograph, it is pointless to exceed the resolving power necessary to obtain all the information from the spectrum of a star. This is limited mainly by atomic thermal motions, giving rise to the Doppler broadening of spectral lines, by turbulence and rotation of the stellar atmospheres in which the lines are formed, and by collisional broadening.

The spherical Fabry—Perot interferometer as an instrument of high resolving power for use with external or with internal atomic beams

1961 ◽  
Vol 263 (1314) ◽  
pp. 289-308 ◽  
Keyword(s):  
High Resolution ◽  
Hyperfine Structure ◽  
Atomic Beam ◽  
Resonance Line ◽  
Resolving Power ◽  
Light Power ◽  
Line Structure ◽  
Fabry Perot ◽  
Atomic Beams ◽  
Very High

The spherical Fabry -Perot interferometer was designed by P. Connes as an instrument capable of realizing higher resolving power than the normal Fabry -Perot interferometer, by virtue of its greater light power at high resolution, and the much lower requirement with regard to accuracy of adjustment. The instrument has now been used successfully in the resolution of structure in the resonance line of the arc spectrum of barium; components with a separation of 2.0x 10 -3 cm -1 have been resolved; they were observed in the absorption produced by a Jackson -Kuhn atomic beam, of high collimation. The instrument has also been used for observing line structure with an absorbing atomic beam traversing the interior of the interferometer; by this means the amount of material required for observing hyperfine structure using an atomic beam , even with very high collimation, can be reduced to a few milligrams, or approximately 100 times less than that required with an atomic beam external to the interferometer, so that enriched isotopes, available in small quantities, can be used; alternatively, adequate absorption can be obtained with much higher collimations of the beam, and correspondingly improved limits of resolution.

scholarly journals High Resolution Interference Spectroscopy Applied to Astronomical Investigations (2000 to 3000 Å)

1971 ◽  
Vol 41 ◽  
pp. 262-262
Author(s):  
B. Bates
Keyword(s):  
High Resolution ◽  
Time Resolution ◽  
Spectroscopic Studies ◽  
Resolving Power ◽  
Angular Dispersion ◽  
Fabry Perot

For orbiting astronomical telescopes and for spectroscopic studies from rocket and balloon-borne platforms the great angular dispersion of the Fabry-Pérot interferometer should permit easier guidance tolerance for a given spectral resolving power with the added profit of the physical compactness of an etalon spectrometer or spectrograph. In addition, the superiority in luminosity and illumination of the interferometer permits shorter exposures and greater time resolution.

scholarly journals The hyperfine structure and zeeman effect of the resonance lines of silver

1937 ◽  
Vol 158 (894) ◽  
pp. 372-383 ◽  
Keyword(s):  
Magnetic Field ◽  
Hyperfine Structure ◽  
Magnetic Moments ◽  
Wave Length ◽  
Zeeman Effect ◽  
Fused Silica ◽  
Resolving Power ◽  
Nuclear Spins ◽  
Fabry Perot ◽  
Quartz Rock

In the work described below, the hyperfine structure of the resonance lines of silver was investigated by the method of absorption in an atomic beam. The intensities of the observed components were measured, and the structure in a magnetic field was observed; from the results the nuclear spins and magnetic moments of both of the isotopes of silver were determined. Experimental 1— The Spectrograph and Interferometer The high resolving power instrument used was a Fabry-Pérot interferometer combined with a 1½-m. spectrograph, fitted with a Cornu quartz prism and quartz rock salt achromatic objectives. The étalon plates were plane to about 1/100 of a wave-length and were coated by evaporation with aluminium. The resolving power of the étalon was about 1/10 of an order for light of wave-length 3100 A; the plates and separating pieces were made of fused silica. The instrument has been described before.

Sensitivity and resolving power of a Fabry-Perot interferometer and of optical mixing spectroscopy

1975 ◽  
Vol 5 (5) ◽  
pp. 547-554
Author(s):  
Vladimir A Alekseev ◽  
V Ya Zel'dovich ◽  
Igor I Sobel'man
Keyword(s):  
Resolving Power ◽  
Fabry Perot ◽  
Optical Mixing ◽  
Optical Mixing Spectroscopy

The fine structure of the line 4686 Å of singly ionized helium

1954 ◽  
Vol 226 (1166) ◽  
pp. 377-392 ◽  
Keyword(s):  
Fine Structure ◽  
Quantum Electrodynamics ◽  
Stark Effect ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Resolving Power ◽  
Doppler Width ◽  
Dirac Theory ◽  
Fabry Perot ◽  
In Series

A liquid-hydrogen-cooled discharge tube similar to that formerly used in the investigation of the fine structure of the a-line of heavy hydrogen has now been used to reduce the Doppler width of the components of the line n = 4 -> n = 3 in the spectrum of He + . The resolving power necessary to separate some components was obtained without sacrificing spectral range by using two Fabry-Perot etalons in series mounted externally to a prism spectrograph. For other components a single etalon was used. Eight components were resolved and their separations measured, and a ninth partially resolved. The positions of certain band lines of hydrogen and helium which lie close to the He + complex and overlap it in different orders of interference were also measured. The relative intensities of the components were broadly in agreement with the relative transition probabilities calculated from the Dirac theory, but some anomalies were observed. From the measurements it is deduced that some of the energy levels are displaced from the positions predicted by the Dirac theory: the 3 S 1/2 level upwards by 0.140±0.005 cm -1 , the 4 S 1/2 level upwards by 0.056 + 0.003 cm -1 and the 4 P 1/2 level downwards by 0.011 ±0.003 cm -1 . These displacements of the S 1/2 levels are in good agreement with the predictions of the new theory of quantum electrodynamics, but the theory does not predict a displacement of the 4 P 1/2 level by this amount. The Stark effect could account for part of the discrepancy, but there remains a disagreement with the theory which exceeds the estimated experimental error.

scholarly journals The Value of Fabry-Perot Interferometry in Studying Long-Term Convective Line Shifts

1999 ◽  
Vol 170 ◽  
pp. 278-285
Author(s):  
Robert S. McMillan ◽  
T. H. Bressi ◽  
J. L. Montani ◽  
T. L. Moore ◽  
M. L. Perry ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Signal To Noise Ratio ◽  
Absorption Lines ◽  
Resolving Power ◽  
Photon Flux ◽  
High Signal ◽  
Dwarf Stars ◽  
Line Spread Function ◽  
Fabry Perot ◽  
Solar Type

AbstractSmall < 10 m s−1 variations of radial velocity (RV) with multi-year periods in solar-type stars may be indistinguishable from the effects induced on lines by stellar activity cycles (Dravins 1985; Saar & Donahue 1997). Dravins (1992) recommended a resolving power R > 3 × 105 to measure accurately the subtle changes in the shapes of bisectors of photospheric absorption lines driven by changes of granular convection in slowly rotating dwarf stars. Butler et al. (1996) measure impressively small amplitudes of RVs by using echelle spectrographs that cover a broad spectrum. However, to cover a broad spectrum the resolving power is typically limited to < 7 × 104, and the necessary presence of the iodine absorption spectrum may make it difficult to measure convective line shifts contemporaneously with the RV time series. Furthermore, to reach an RV accuracy of ± 3 ms−1 the whole profile of each line is used, thus maximizing the possibility that changes in the shapes of the lines’ C-bisectors could induce an apparent variation of RV.Dravins (1985) recommended the exclusive use of the steep flanks of photospheric absorption lines to minimize the effects of convection on apparent RV. McMillan et al. (1993, 1994) demonstrated that such RV measurements made with a Fabry-Perot etalon (FPE) interferometer in transmission can be stable in the presence of stellar line variations seen by other investigators whose measurements were not based exclusively on line flanks. Dravins also prescribed high resolving power, high signal-to-noise ratio, high instrumental contrast, and low instrumental wings to analyze the rest of the line profile for convectively-driven changes (Dravins 1978, 1987, 1992). A double- or multiple-pass FPE scanning whole line profiles can provide high R, high contrast, low wings, and a stable, symmetrical line spread function with small (portable) optics, although the low photon efficiency will restrict its use to a few carefully selected stars. The spectral classes of these stars should span the spectral classes of the stars being monitored by others for planets. We describe a possible implementation of this concept that has the potential for adequate photon flux: observing symbiotically through another instrument on a 6-m to 10-m class telescope.

scholarly journals UNSWIRF: A Tunable Imaging Spectrometer for the Near-Infrared

1998 ◽  
Vol 15 (2) ◽  
pp. 228-239 ◽  
Author(s):  
Stuart D. Ryder ◽  
Yin-Sheng Sun ◽  
Michael C. B. Ashley ◽  
Michael G. Burton ◽  
Lori E. Allen ◽  
...  
Keyword(s):  
Near Infrared ◽  
New South ◽  
New South Wales ◽  
Resolving Power ◽  
Imaging Spectrometer ◽  
South Wales ◽  
Fabry Perot ◽  
The University

AbstractWe describe the specifications, characteristics, calibration, and analysis of data from the University of New South Wales Infrared Fabry–Perot (UNSWIRF) etalon. UNSWIRF is a near-infrared tunable imaging spectrometer, used primarily in conjunction with IRIS on the AAT, but suitable for use as a visitor instrument at other telescopes. The etalon delivers a resolving power in excess of 4000 (corresponding to a velocity resolution ∼75 km s−1), and allows imaging of fields up to 100″ in diameter on the AAT at any wavelength between 1·5 and 2·4 μm for which suitable blocking filters are available.

An attempt to measure interferometrically the widths of chromospheric lines at the total solar eclipse of 25 February 1952

1953 ◽  
Vol 216 (1125) ◽  
pp. 183-193 ◽  
Keyword(s):  
Optical System ◽  
Solar Eclipse ◽  
Total Solar Eclipse ◽  
Resolving Power ◽  
Atmospheric Transmission ◽  
Concave Mirror ◽  
Minimum Width ◽  
Interference Fringes ◽  
Fabry Perot ◽  
Quartz Spectrograph

An attempt has been made to measure with a Fabry-Perot interferometer the half-value widths of lines of the chromosphere during the total solar eclipse of 25 February 1952. The optical system consisted of a coelostat and concave mirror, an etalon with aluminized quartz plates, quartz fluorite achromats and a quartz spectrograph; the chromospheric spectrum could thus be observed to the limit of atmospheric transmission. The separation of the plates was 3·1 mm, the spectral range 1·6 cm -1 , and the resolving power realized was 170000 over the whole range of spectrum from λ 4800 to λ 3100. This arrangement allowed temperatures to be measured down to 5000° K, and turbulence up to 17km/s. Besides the lines of hydrogen, helium and ionized calcium, a number of metallic lines were observed, most of which were blended. No interference fringes were found in any of the lines. Experiments were made to ascertain how far such fringes might be hidden by the uneven structure of the chromospheric arcs. As a result of these experiments it was concluded that the minimum width of the unblended lines was 1·2 cm -1 , and of the blends 0·5 cm -1 , this lower value being equivalent to 0·06 Å at λ 3500 or 0·10 Å at λ 4500.

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