Comments on the optimization of high resolution  
Fabry-Pérot filtergraphs

Scharmer, G.

doi:10.1051/0004-6361:20052981

Cited by 161 publications

(149 citation statements)

References 9 publications

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“…We assume a working wavelength of 5000 Å and an f -number which ranges from 64 to 512. The results we finally obtained are very close to those quoted by Scharmer (2006) both before (Table 1, fourth column) and after (Table 2, third column) correction for the defocusing effect.…”

Section: Tesos: a Case Studysupporting

confidence: 88%

“…We want to emphasize, however, that this procedure correctly takes the phase effect introduced by the interferometer into account with no need of approximations other than those intrinsic to the scalar theory of diffraction. Any defocusing effect produced by the interferometer, as that described by Scharmer (2006), spoils the PSF which might be better on another plane. To compensate for such an effect, we place an additional numerical lens on the system entrance pupil, computed as…”

Section: The Telecentric Mountmentioning

confidence: 99%

“…If the lens and FPI are both optically perfect, the field and the intensity PSFs will be those predicted by the diffraction theory for a plane wave passing through a circular aperture, since an ideal FPI does not change the planarity of the incoming wavefront. The phase shift affecting rays not parallel to the optical axis (Scharmer 2006) introduces a phase factor that only depends on the focal plane coordinates and is therefore canceled when evaluating the intensity. If we add a narrow band filter to our system, with a bandwidth less than one FSR, we would observe a transmission ring system superimposed on the image of the sky, as predicted by the FPI theory.…”

Section: The Classic Mountmentioning

confidence: 99%

“…Steel (1967) and Ramsay (1969) made a first evaluation of these effects, limited to the case of parabolic and planar distributions of errors. Beckers (1998), von der Lühe & Kentischer (2000), and Scharmer (2006) examined the imaging properties of a multi-interferometer in both classic and telecentric mounts. Moreover, Martinez Pillet et al (2004) and Alvarez-Herrero et al (2006) have recently carried out a detailed study of the image quality of a dual Fabry-Perot in CM for the IMaX instrument of the Sunrise mission.…”

Section: Introductionmentioning

confidence: 99%

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Imaging performance of multi-etalon bidimensional spectrometers

Righini

Cavallini²,

Reardon

2010

A&A

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Aims. In recent years, several new solar and nighttime panoramic spectrometers based on Fabry-Perot interferometers have been successfully developed. In this paper we evaluate the imaging performance of the two types of mountings that have been adopted, telecentric and classic, in particular trying to understand which one might be more suitable for future large-aperture solar telescopes. Methods. Numerical code was written to simulate the behavior of such spectrometers, on the basis of the theory of Fourier optics. This code was used to simulate different instrument configurations and was tested on previous results obtained either analytically or numerically by other authors. Results. Calculations of the system MTF and Strehl ratios show that both mountings may perform very close to theoretical expectations. However, gap irregularities in the interferometers may alter the optical quality of the monochromatic images. In the case of the classical mounting in a collimated beam, it is possible to partially compensate for the resulting errors in the wavefront emerging from the interferometers with a suitable phase plate. We also performed an observational test of the optical quality delivered by the IBIS interferometer installed at the Dunn Solar Telescope of the National Solar Observatory, with the results substantially confirming the calculations. Conclusions. It follows from our results that both mountings may be efficiently used for solar bidimensional spectroscopy. The final choice depends on the tradeoff between factors such as image quality, field of view, and acceptable wavelength shift.

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Section: Tesos: a Case Studysupporting

confidence: 88%

Section: The Telecentric Mountmentioning

confidence: 99%

Section: The Classic Mountmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Imaging performance of multi-etalon bidimensional spectrometers

Righini

Cavallini²,

Reardon

2010

A&A

View full text Add to dashboard Cite

show abstract

“…1). Besides, the narrow-band frames from TESOS with its telecentric mounting exhibit an "orange peel" pattern, and the spectral lines from the scans are locally shifted with respect to the scanning step number and may suffer from asymmetric transmission profiles (Scharmer 2006). These are caused by wavelength shifts of the transmission peaks of the Fabry-Perot etalons, due to (small) local flatness defects of the order of λ/200 (in the visible range) and due to mistuning of the etalons against each other.…”

Section: Discussionmentioning

confidence: 99%

On acoustic and gravity waves in the solar photosphere and their energy transport

Kneer¹,

González

2011

A&A

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Aims. We study acoustic and atmospheric gravity waves in the quiet Sun to estimate their energy transport to the chromosphere. Methods. A two-dimensional time sequence from quiet Sun disc centre was analysed with simultaneous spectroscopic observations in Fe i 5576 Å and Fe i 5434 Å (both with Landé factor g = 0). We calculated response functions of the velocities for the line minimum shifts and atmospheric transmissions of waves for the two lines. For this, NLTE line formation in granular and intergranular model atmospheres from numerical simulations were performed. For the interpretation of the observed waves and for the estimates of energy fluxes, we assumed adiabatic propagation of plane waves in an isothermal model atmosphere. Fourier analyses of intensity and velocity fluctuations were carried out. They yield power, phase, and coherence as functions of frequency ν (from temporal Fourier transforms) and in the k h −ν plane (from three-dimensional transforms). The power spectra, together with the mass densities at velocity formation heights, give then the energy fluxes. Results. The rms velocities found here in the acoustic and gravity wave domains are lower by a factor ∼1.5 as in earlier work. We therefore admit a factor of 2 for an upward correction of the estimated fluxes. For acoustic waves we find: 1) upward propagating waves are present on the Sun with frequencies up to 14−15 mHz (periods U ≈ 70 s); 2) the approximation of plane adiabatic waves in an isothermal atmosphere appears adequate for estimating the energy fluxes; 3) the acoustic energy fluxes are in the same range as found in our earlier work from ground-based, two-dimensional spectroscopy, 1500−3100 W m −2 at an atmospheric height of ∼380 km and 1300−2700 W m −2 at 570 km. The energy flux carried by gravity waves is difficult to determine. We find: 1) phase and coherence spectra between continuum and velocity fluctuations show that convective overshoot and gravity waves are superimposed. We account for the convective flows using these coherence spectra. 2) At low frequencies, the vertical wavelength Λ z can be short ( 300 km), yielding large corrections for atmospheric transmissions (factors >100). We thus exclude from the flux estimates waves with |k z | > 20 Mm −1 and with vertical group velocities υ gr,z < 0.3 km s −1 . They are likely to be strongly reduced in amplitude by radiative damping. 3) With these caveats, the energy fluxes carried by gravity waves are found in the range of 4000−8200 W m −2 at 380 km and 700−1400 W m −2 at 570 km. Gravity waves thus also contribute to the energy transport into the chromosphere.

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Scientific objectives and capabilities of the Coronal Solar Magnetism Observatory

et al. 2016

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Magnetic influences increase in importance in the solar atmosphere from the photosphere out into the corona, yet our ability to routinely measure magnetic fields in the outer solar atmosphere is lacking. We describe the scientific objectives and capabilities of the COronal Solar Magnetism Observatory (COSMO), a proposed synoptic facility designed to measure magnetic fields and plasma properties in the large‐scale solar atmosphere. COSMO comprises a suite of three instruments chosen to enable the study of the solar atmosphere as a coupled system: (1) a coronagraph with a 1.5 m aperture to measure the magnetic field, temperature, density, and dynamics of the corona; (2) an instrument for diagnostics of chromospheric and prominence magnetic fields and plasma properties; and (3) a white light K‐coronagraph to measure the density structure and dynamics of the corona and coronal mass ejections. COSMO will provide a unique combination of magnetic field, density, temperature, and velocity observations in the corona and chromosphere that have the potential to transform our understanding of fundamental physical processes in the solar atmosphere and their role in the origins of solar variability and space weather.

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Comments on the optimization of high resolution Fabry-Pérot filtergraphs

Cited by 161 publications

References 9 publications

Imaging performance of multi-etalon bidimensional spectrometers

Imaging performance of multi-etalon bidimensional spectrometers

On acoustic and gravity waves in the solar photosphere and their energy transport

Scientific objectives and capabilities of the Coronal Solar Magnetism Observatory

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